By on November 29, 2016

1998 Toyota Sienna XLE Front 3/4, Image: Toyota

TTAC commenter MatadorX writes:

Sajeev, I wonder if you wouldn’t be able to offer some of your wisdom on the continuing saga of the van.

The new automatic went in and worked perfectly. The engine got fully rebuilt. New crate short block direct from Toyota, heads rebuilt-surfaced/valve job/adjusted/stem seals. Entire engine re-gasketed with Toyota FIPG/OEM gaskets. New pretty much everything else on the front of the car. Wires, plugs, all three O2 sensors (Denso), IAC, Coolant Temp sensor, MAF, resealed injectors, OEM fuel filter. Brand new main TWC catalytic converter. Converted both the exhaust manifolds to 1998 Sienna California emissions spec (integrated warm-up cats), so now the car has a total of THREE catalytic converters.

Broke in the entire setup for 1,000 miles the proper way with varying RPMs, letting off gas to allow rings to seat, and occasional three-quarter throttle bursts, special break in oil for the first 500, then over to Mobil1. Tons of power, smooth, quiet. At idle she is so smooth you can’t even tell the van is on. Checked the entirety of the engine for vacuum leaks — nothing. Compression is strong across the board. Zero blow by.

However, I live in California, and — you guessed it — the van still failed the smog check.

I am failing HC Hydrocarbons at 25 miles per hour, and barely passing at 15 mph. Other emission categories are actually fine. My best test:

HC:
15 mph MAX: 47 ppm, MEAS: 47 ppm
25 mph MAX: 31 ppm, MEAS: 49 ppm

As you can see, the standards are incredibly low for my specific vehicle which came new in 1998 with 1994 technology: one cat three feet from the engine, no EGR, old-school heated O2 sensors (not A/F ratio sensors), wasted spark coils, and no VVT-I. Most vehicles are a pass if under 70 ppm here, or below 200 ppm for any other state. I have tried warming the car as hot as possible before the test, using 91, 89, and 87 octane (no real difference between those). I even tried the denatured alcohol trick, which had ZERO effect on my numbers — it just raised my NOx. I also tried one higher heat range plugs, but again the numbers actually got worse.

If I had to guess, the engine is pretty much already as healthy as it is ever going to be. I am about out of options. Registration lapsed four months ago (paid, so no penalties but can’t get my tags). I think the only thing I could do would be find a shop to rent with a dyno/exhaust gas analyzer, and pay the best tech they have to mess with it to try to get it through. This is pretty much the nuclear option, as the cost would likely run into the $1,500-2,000 range, according to estimates I got. Honestly, as far as this has gone, I would be willing to spend that if I knew 100 percent that this could make it pass, but finding the right shop with expertise in SoCal that wouldn’t laugh me right out of the place with the stock minivan would be nearly impossible.

Nine-tenths of shops here, if they are any good, require you to convince them to work on your car, which is honestly why I became such a competent shade tree.

I love my van, it has immense sentimental value to me, and I am willing to do what I have to in order to register it. I just want my baby back. I scored an amazing deal on a leftover 2015 XB 5MT the dealer really wanted gone in May. Basically, I should be able to sell it used for around what I paid new within two years if I keep it under 20,000 miles — so at least I have something to drive to work with a warranty for just the cost of reg, tax, and gas, but it just isn’t the same as the “fat” Toyota quality of the 1990s.

Any feedback you or your readers could offer would be very helpful, especially as relating specifically to California smog.

Sajeev answers:

This takes me back to the sadness/frustration felt when my Mark VIII wouldn’t pass emissions.  I did everything to make it pass Texas’ low and high speed dyno emissions test.  It always failed the high speed test, until a savvy muffler/speed shop said my RandomTech cats have a unique internal shape that performs poorly under 1500 rpm, which was my problem (third gear, 1100 rpm, 25 mph) at said high speed test. So I locked that sucker in second gear and all is well!

Immense sentimental value in mind, you and me seem to be cut from the same cloth! So let’s spitball some ideas:

  • Is your rear (aftermarket) cat the same basic design?  You never know, maybe testing at higher RPMs at those speeds might help!
  • Replace any soft/brittle/cracked vacuum lines under the hood
  • I want to say you should check fuel pressure but that might just be me reading ahead.  So without any further ado… 

MatadorX concludes:

Figured I’d send an update: she finally passed! Flying colors.

It ended up being something to do with the fuel pressure regulator and pump, two of the few things I didn’t replace on the rebuild, but did at the end just to make sure all bases were covered. Also went over to a California spec 3 catalytic converter setup, with the front two coming from a donor car (huge money new) and the rear main an aftermarket unit that is Cali legal. Pretty much no emissions, according to the final test sheet. Happy to have the van back again. Thank you for the tips/encouragement!

 [Image: Toyota]

Send your queries to [email protected] Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

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40 Comments on “Piston Slap: To Love A Sienna Like No Other? (Part II)...”


  • avatar
    heavy handle

    That’s exactly what I guessed from reading the letter: aftermarket cat. They are never as good as OEM, even used OEM.

  • avatar
    87 Morgan

    Great work getting your beloved to pass smog and safety.

    The OP is truly one of a kind. I have either met or known people who were ALMOST as passionate about their Chevelle/Nova/GTO/Mustang/GNX (insert your appropriate ride) as the OP is with his Toyota van. Fantastic passion, I love it.

    • 0 avatar
      PrincipalDan

      When you start searching forums you find there is an enthusiast community for just about everything.

      There are guys that are more passionate about their Patriots than you would think any sane person could be.

  • avatar
    IBx1

    Why anybody subjects themselves to this batsh!t-insane level of kommunism and enjoys it is beyond me. You easily just spent 3x the blue book of the van and lost months of time trying to pass an emissions inspection, when you could just come to another state that isn’t kali and enjoy your vehicle in good repair without worrying about minuscule emissions overages. Plus you wouldn’t pay nearly as much in taxes, so you can recoup your sunk costs. Just don’t vote for tax raises if you do move out.

    • 0 avatar
      heavy handle

      You seem to be very confused as to what communism is or isn’t. Having a law that punishes littering, or polluting, isn’t communism by any stretch of the imagination. It’s just good old-fashioned American “your freedom ends where mine begins.” In other words, you can do what you want to yourself, but you can’t harm others without expecting them to fight back.

    • 0 avatar
      ericb91

      Oh sure! Why didn’t he just pack up and move out of California? Find new employment, new schools for the kids, new real estate, etc.

      Sure he put a lot of money into the car. It’s not about Blue Book Value. If your treasured loved one owned a vehicle (say a Bel Air or something else cool/classic) and they left it to you when they died, one could see why you would hold on to it. Sentimental value is a very different thing than Blue Book value. I don’t recall him saying “I hope to sell this and make lots of money!!” but I do recall him saying “This van has a lot of sentimental value to me”.

      Ugh, now I’ve fed the trolls…

    • 0 avatar
      PeriSoft

      Emissions testing is *totally* the same as workers controlling the means of production.

    • 0 avatar
      stevelyon

      I subject myself because I like living in a beautiful place that has clean air, and I don’t mind paying more for it.

  • avatar
    seth1065

    Glad you got your ride back on the road, you deserve many more years with you loyal car and it deserves a owner like you, I am sure Gramps is smiling w pride for you both, check back in at 400,000 miles.

  • avatar
    dividebytube

    So glad I don’t have to deal with emissions testing. Not that any of my cars are showing check engine lights or have removed pollution devices, but what a pain if you’re driving an older car and don’t have money for a non-critical repair.

    I imagine a small percentage of drivers in Michigan are abusing are no emissions testing: I hear a lot of headers exhausts on trucks. And also any number of modified cars owned by teenagers or enthusiasts.

  • avatar
    jmo

    A guy pissing away a fortune to keep his heap on the road is to be praised but another losing the same amount trading a car every few years is the worst thing ever?

    • 0 avatar
      OldManPants

      His “heap” is of an irreplaceable quality and ergonomic excellence that new cars don’t have to match in order to be bought by guys like you.

    • 0 avatar
      jhefner

      It is a matter of priorities/finances.

      Many people who drive clunkers do so because they cannot afford new. When it comes to shear economics and nothing else, it does not make since to repair instead of replace.

      In this case, it is someone who can afford to repair it if he wishes. Frankly, 99% of the time; you will never get back what you put in restoring an old car, whether you are talking a Toyota Sienna or any other car someone else might find worthy of restoration. It is not about what makes financial sense; it is purely an emotional decision.

    • 0 avatar
      87 Morgan

      JMO: I think you are a bit harsh here. It appears the OP has plans to use his Sienna as a DD or secondary DD as he notes that he has a scion he can get out of fairly clean. So, if he puts 4k into the van + ends up a with a 2k loss on the Scion (he thinks he will come clean on it, I seriously doubt that will be the case) he is 6k into this restoration project.

      If he drives the van another 50k miles he is 12 cents a mile. Another 100k 6 cents a mile. How is that pissing money down the drain? What if he instead leased a car for 36 months with 2k down at $250 a month? Well that is 11k down the drain AND he has to return the car.

      As far as pumping money into old cars…I am guilty of that yes. I have zero expectation of getting my money back. But, my children 11 & 13 can turn wrenches and problem solve an older car better than most adults today. What’s that worth?

  • avatar
    vvk

    I once had a problem passing emissions. After doing some basic engine stuff it passed after I installed a new cat. A 1988 Volvo 245 manual. Loved that car. Bought it for a trip to Alaska, then gave to a friend to sell in Canada. It failed Ontario emissions when he registered it…. guess the $100 aftermarket cat stopped working after 12k high speed miles. Ended up making several thousand dollars on that car. What a superb car, easily one of my favorite!

    • 0 avatar
      MatadorX

      Yep the aftermarket cats aren’t great for longevity. The best way to go here in Cali is have a smog Cat and a good used original to run for the other 2 years between tests.

  • avatar
    dukeisduke

    Wow, he jumped through more hoops than I’d be willing to. My last vehicle (’95 F-150 with 302/4R70W) just barely passed HC on the Texas 15/25 ASM test, a couple of years in a row. EEC IV system, one HO2S (which I replaced at 150k), and the original cats. Then the last time I got it inspected (with like 210k), HC was much better? Why? I don’t know. I suspect it probably need a new PCM, because I was getting a 565 code (CANP circuit failure) for several years, which I dealt with by disconnecting and plugging the vacuum hose at the TB (it would stall at idle because of the vapors being drawn in). When I went for inspection, I would reconnect it, using a section of hose that had a pin stuck in it, to block the vapor flow (it always passed somehow).

  • avatar
    MatadorX

    Thanks for the kind words guys. Believe me well aware I live in the least car friendly state to have such a passion for old cars. It does have other benefits though like weather, high paying jobs, and extreme insulation from political climate of D.C. Luckily the rest of the fleet is smog exempt (pre 76) AMC iron so no real issues there.

    I think what it came down to, other than slightly too high fuel pressure, was that Cali recently went to new smog standards.

    They basically don’t tail pipe test 2000+ cars (just OBDII scan), lowered slightly the standards for OBD1 and earlier cars (1995-1976) and absolutely KILLED the 1996-1999 early OBDII cars with really tough to beat levels. Other brands 1996-99 have few issues passing these tough new standards, but brands like Toyota, that on Federally sold cars (like mine) skated by with outdated single cat/v6 apps through 2000, not putting pre cats on until 2001, this is a huge issue to pass. I have a theory Toyota pulled an early form of the VW stunt, as the CEL will not set readily if at all for CAT inefficiency on these federal OBDII single cat models. Then in 2001 they over compensated by having ECU’s that throw cat inefficiency complaints at so much as a change in the weather.

    ….Anyhooo when Cali made the new standards, even though the 2000 Fed Sienna and the 1998 Fed Sienna both use the same setup, one gets to coast by with just no CELs/Monitors set, and the other, mine, must pass just like a 1998-1999 CALI emission spec 1998 Sienna, which oh BTW has: Three cats, integrated EGR valve, modern Air/Fuel ratio sensors instead of basic 02s, and an ECU with strict emission logic to top it all off.

    …Basically the only way for me to pass was cheat. I needed, at minimum, the three cat system to pass. One huge issue, here in Cali you can’t just go buy cats, they must have a CARB approved stamp on them. And you can’t buy them used. So either OEM, which for my van would mean a $1,500 front y pipe with integrated rear front and rear main cat+ $750 front manifold with integrated cat=$2250, or a CARB approved aftermarket set. Well the rear main is easy to get in universal aftermarket CARB approved. $150 from Summit. But the front Y pipe and integrated manifold cat? NOPE! Since few 1998 Sienna’s were sold with Cali 3 cat emissions, the aftermarket only bothered to certify their setups for 1999-2000 Siennas. Same part from 1998-00 but CARB/Smog would fail me based on this.

    Only option, was to find a used, low mile, sufficiently rusty (superficial rust) set of front cats, get them shipped in from out of state (illegal to sell used cats in Cali) and marry them with the new legal rear main to pass. Smog guys don’t car if your on original rusty cats, but if new and shiny, they better have the CARB number on them or you are failing. Getting a 5.5 foot long y pipe shipped was challenge, but for $300 I had both used cats, bolted on the new CARB approved rear main, and the numbers finally dropped, to zeros.

    Whewwww!!

    • 0 avatar
      yamahog

      In all seriousness, you da man! Those MZ series V6s are nice, I like them way more than the current GR V6s. Way to treat the car right and figure this out! Awesome story! Sucks you got the tough consideration but you got through it and now you have a story!

      • 0 avatar
        dukeisduke

        The GRs are good engines, with chains instead of belts, and VVT-i. The only real problems they’ve had were the VVT-i oil hose issue (which can be replaced by the later rigid line setup), and some have piston slap when cold (like my wife’s ’08 Sienna)

    • 0 avatar
      IBx1

      My earlier comment was meant to point out exactly this; those tests are extremely unfair to people in your situation. I have no issues with you keeping your much-beloved car on the road, but it’s ridiculous that you are forced to pay so much to do it. If the car is in good repair, all lights working, tread on the tires, brakes able to stop the vehicle, and not fogging out the road with oil burning or something like that, a simple CEL on/off test should be it. Even with the OBD-I cars, if the car is mechanically sound it should be up to the discretion of the inspection station to allow a few ppm over the limits.

      Even if you wanted a straight pipe exhaust, there’s very few people on the scale of the hundreds of millions of cars in this one country who would do that, and it would have a negligible effect on smog. As for me, straight pipe 7.3L PSD, emissions-exempt in Texas.

      • 0 avatar
        87 Morgan

        As for me, straight pipe 7.3L PSD, emissions-exempt in Texas.

        so….you have a diesel douching bro-dozer spewing black soot all over? nice one. Merica’.

        • 0 avatar
          IBx1

          87 Morgan,

          Why would I want to make smoke? That’s wasted fuel that didn’t become horsepower and a bad image. My truck didn’t come with a catalytic converter from the factory and that’s why it’s exempt; all I did was make it sound better and got clean tunes for better efficiency. 2WD + 6MT = 25MPG, respectable for a 6,000lb+ crew cab.

          • 0 avatar
            DC Bruce

            Well, of course you are “legal” but, as VW can tell you, with a diesel, the absence of “smoke” is only part of the problem (and I betcha you smoke on hard acceleration). The other part is NOx, which is invisible and which makes nice soupy smog when heated — and boy does Texas have heat. The DPF in “clean diesels” eliminates the smoke (by trapping the particles of unburned fuel) and is a fairly simple implementation. The tougher challenge in a diesel, with high compression is that high combustion temperatures promote NOx formation. To deal with that, cooled EGR is used. The EGR coolers on subsequent PSDs (the 6.0 especially) were a huge failure point, costing their owners lots of money.
            Don’t get me wrong, I think it’s unfair to impose emission standards on older vehicles “retroactively” i.e. more stringent than those extant when the vehicles were sold new. But there’s little doubt that your truck throws out a lot more nasty stuff than the current 6.7 PSD, smoke or no smoke.

    • 0 avatar
      rpn453

      That’s some fine work there, MatadorX.

      • 0 avatar
        IBx1

        DC Bruce,

        With my hottest tune setting, there is a quick puff when I mat the throttle, but thanks to the guys at Gearhead Tuning and the upgraded compressor wheel and up-pipes I put in, the turbo spools up fast and the exhaust cleans up to a faint haze. Because of the tendency towards soot, I’m making less NOx and less smog, while not producing enough soot to make everyone hate my truck. This is the last engine designed before emissions testing for diesels, so you’ll smell the distinct diesel exhaust no matter if I’m pushing it, but I keep it in good repair like it was when it was new, and drive responsibly. As a bonus, the truck has 258,000 miles on it, so I’m not contributing to new vehicle manufacturing material consumption and emissions!

        New diesels are nightmares because of the unreliable emissions equipment; full deletes and clean tunes are the way to go so you can get 500,000+ miles out of them.

  • avatar
    jhefner

    I have the fortunate setup that the very shop that got the Blue Goose running after sitting up for four years is on the opposite side of the block from one of the few shops that can test pre-1996 (OBD-II) cars. He already refers to it as my pet car.

    It passed emissions with few problems until the last couple of years. (My guess is that the original cats have about had it.) When it fails, I just drive it around the block to him, a few days later I pick it up with a new tag and pay him $75 for his trouble; the amounts they are quoting you is unreal.

    I asked last year what did he do to get it to pass; apparently he was standing over the engine while it was running on the rollers; tweaking something while it ran to get it to pass.

    Playing this game a couple or so more years until it is finally considered an antique and it no longer needs to pass emissions.

    Besides the above tips; it pays to have a good relationship with a mechanic; I have brought him lots of business, and always try to maintain a good working relationship with him.

  • avatar
    Driver8

    I admire your gumption. A+

    The next time I’m choking on fumes behind a landscaper’s truck or clapped out Civic, I’ll think of you. At least we don’t have coal rollers here.

    • 0 avatar
      jhefner

      I don’t know if you are talking to me or the OP; but in my case you would rarely if ever find yourself choking on my fumes even if you lived on my street. I stopped DD it several years ago; it mostly lives under a cover on my driveway now.

  • avatar
    MatadorX

    That’s the key, you are running on the original cats. When every components is new, there are no more tweaks, especially on a OBDII based platform. The issue here was primarily converting over to a totally different exhaust system from new and getting cats that were legal, other than OEM units, which turned out to be zilch. The 1MZ-FE, while a beautifully reliable smooth engine, isn’t the cleanest design around (they had to heat the heads to 250deg+ to pass emissions to sell in the USA, which led to a huge sludge recall…) so it needs cats performing at peak to run clean, and ideally three of them, as just one will under-perform unless red hot, and likely die quickly unless $1500 OEM.

  • avatar
    PRNDLOL

    Back in the early 2000’s whenever I was due for the Ontario’s 2 year DriveClean I would run the tank dry, put in 15 bucks of premium and change the oil just before. Someone once told me that dirty oil and lousy gas were big part of failing the emission test, and I was still passing a GM 3.1 with 400,000 km on it.

    • 0 avatar
      vvk

      My old SAAB was passing the dyno emissions test with 300k+ miles on it. Until my mechanic figured out that he did not HAVE to put it on the dyno because it was front wheel drive and had a hand brake acting on the front wheels. Which is the setup my state law makes an exception for because there is no way to reliably and safely fix the car in place during testing. The car basically had no emissions when tested without load. Zeroes everywhere.

  • avatar
    pwrwrench

    My first thought, even before I got to the end of the original story, was; Did anyone check the fuel pressure?
    Since the pump and regulator got replaced I suspect that the pressure was above specs. This can overwhelm any efforts of the PCM, O2 sensors, and CATs to control effectively.
    Certainly CATs ability to reduce HC, CO, and NOx will decrease over time, but I’ve seen vehicles that are more than 20 years old with 200K miles on them pass emission tests. If the motor had worn to the point of letting a lot of oil into the combustion chambers that will stop the CATs working.
    Also shops in CAL can be wary of working on vehicles like this. It can be an expensive headache to get them emission compliant. The CARB regularly sends out ‘undercover’ cars to trap shops that are certifying and repairing ones that are not in compliance.
    Also only “Test and Repair” stations can legally prep cars to pass emission tests here. Other shops can get around this by repairing “Driveability” problems or doing “tune-ups”.

  • avatar
    cgjeep

    I applaud the owner for doing this to a car he loves. But I don’t understand why he has a minivan if he isn’t married. Because no wife would allow this kind of time/money to be spent this way.

  • avatar
    indi500fan

    I must say well done!
    Given the rust free California chassis, this makes a lot of sense, and could well provide another 2 decades of useful life.

    • 0 avatar
      gtemnykh

      This was my thought exactly. If it weren’t for rust-related maladies, I probably would still be motoring along in my ’98 MPV. Part of me wants to find a clean California example of an early 90s V6 4wd model.

  • avatar
    st1100boy

    You know there’s another way to skin the cat on the smog test: Register the car illegally in another state without smog testing. There are any number of states who will happily take your money and issue a new title and plate, all by mail. If you park the car inside each night, you’ll have little to fear from jerk neighbors turning you in. And if you do get pulled over, if you’ve got a good drivers license and insurance, you’ll likely be OK. When in doubt, lie and say it’s your son’s/father’s car, you just brought it in from your out of state second residence, whatever. I may know of a guy who has regularly registered vehicles out of state for 20 years+, and picked up a traffic ticket or two along the way…no drama.

  • avatar
    pwrwrench

    Law enforcement in California is on the lookout for vehicles registered out of state that ‘live’ here. Big clue is having a Cal driving license with the car registered in a different state. With the computer record keeping it won’t take long to find out how long this has been going on.
    California wants the money from registration and will impose fines and penalties if they find someone doing this.
    Of course I have heard ‘rumors’ of people doing this for a long time. Just don’t get caught speeding or going through a red light.
    Sometimes there are checkpoints where the police are not only looking for intoxicated drivers, but do complete driver’s license/registration checks. Cars with out registration, insurance, etc often get towed to impound.

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