#O2Sensor

John writes:

I recently had a local shop confirm the need for O2 sensors in my Jaguar S-Type. With 97,000 miles on them, it seems very likely they need replacement, and the mechanic wants to install factory sensors at the cost of some $650 for the parts. I can purchase Denso or Bosch from the local parts store for less than $200. As these parts were originally designed to last at least 80,000 miles (Federal warranty requirement), I figure that replacements from any reputable source will last quite a long time.

What is your opinion as to brand specific parts versus more generic replacement parts?

I suspect the original supplier was actually Bosch anyway so in my mind they are the same.

Geoff writes:

Sajeev, I enjoy your TTAC contributions very much. I have a 2002 Dodge Ram with a 5.9 liter V8. Starts every time and idles fine initially. But just when it transitions over from the cold start sequence to Normal running it starts to act as if it is gasping for air.

TTAC Commentator Dave M writes:

Hey Sajeev!

A question for you and B/B. Especially during cold weather my Trooper gets a ’clunk’ shifting from 1-2 (it’s a 4 speed automatic) and then back down. This coincides with a CEL. It doesn’t happen all the time. There are other times (even during cold) where the truck runs normally – no clunk, no CEL. Checking the CEL code and it indicates all four oxygen sensors (replaced last year); when no CEL no code to read.

My first thoughts were it might be time for ANOTHER transmission. But my brother says no, it has to be electrical since it’s intermittent. Any ideas where to start?

Hi Sajeev,

You asked for some emails, so here’s one from me. It may not be Piston Slap worthy, but it’s got me confused. Here’s my problem:

I have a 1998 Nissan Frontier. 150k miles, 2.4l four banger. It threw a Service Engine light on me the other day. The code is a P0301, i.e. cylinder #1 misfire. Figuring it was a spark plug issue, and since I was about due for a tune up anyway, I replace the plugs, wires, distributor cap and rotor. I cleared the code with my scanner, and….it came right back. I did a little creeping on the Nissan forums, and the consensus seems to be that this results from clogged EGR passages. So this past weekend I decided to clean them. I was lead to believe that this would be a cake walk. All that was required was to remove the set screws between the intake runners, spray some carb cleaner in there and scrub them out. Easier said than done. Removing the screws was not too bad, but putting them back in after cleaning was nigh impossible. 5 hours and sawed off 8mm Allen wrench later, I had the plugs back in. My truck ran great! For 20 minutes. Then the code came back. Now I’m pretty much flummoxed. The way I see it, my options are:

1. Remove the air cleaner assembly and manifold screws again and try cleaning them more thoroughly with a pipe brush and more carb cleaner
2. Try something like Seafoam through a vacuum hose. I am reluctant to do this as I’m not 100% sure which hose to use and opinions on Seafoam are mixed
3. Take my vehicle to a mechanic for a more professional diagnosis. I do have access to a reputable independent mechanic who specializes in Nissans and Toyotas

So, what do the B&B think? Anyone else had this problem with a Nissan KA24DE 4 cylinder?

Thanks for your help.