Yet another problem (P0432 error code - cat-related)

Hey everyone,

So if it's not one thing, it's another... Exactly a week after buying my 2001 XJ Sport, my check engine light came on. A quick stop at Advance revealed the following error:

P0432
Main Catalyst Below Threshold (Bank 2)

The research I've done thus far has yielded conflicting information (some say it's an indication of a bad O2 sensor up near the pre-cats, others say further down the exhaust system, and so on). I know it's difficult to conclusively identify exactly what's triggering this code, but does anyone have personal experience with this error? And if so, what was your fix? I'm hoping to avoid as much of a wild goose chase on this one as I can, so please share your thoughts. Thanks!

Just found a good thread about this, actually:

http://www.jeepforum.com/forum/showthread.php?p=3123944&posted=1#post3123944

Looks like I'm off to buy an O2 sensor and pray it makes the issue go away...

Well that was fun... I went ahead and installed my new Sensa-Trac shocks up front while PB blaster soaked into the rear manifold ("Bank 2") downstream O2 sensor's threads... It's all done now, and has been taken for a quick test drive.

Only thing is the check engine light is still on... I've read a few other threads that imply that within a short time of driving (maybe a few trips), the light should turn off if the problem has been solved thus negating the need for me to manually reset it (either by disconnecting the battery or taking it by AutoZone/Advance to have them reset it)... Is this true?

Bump...

Anyone? I ran through the cluster diagnostics (off -> on 3x while holding the trip reset button) but that doesn't reset the CEL on my 2001. Do I need to resort to disconnecting the battery for a few minutes?

Like I tell the family... I'm not crazy, I just love talking to myself.

I went ahead and disconnected the battery for a few minutes to reset the light. If the problem doesn't come back in the next 300 miles (or tank of gas, which ever comes first... probably the latter) I'll resurrect this thread and document my findings in case some other poor sap runs into this issue again in the future.

For the hell of it, I'll go ahead and let you guys know I replaced the post-cat O2 sensor on Bank 2 (the 3 cylinders nearest the firewall) with an OE-style Bosch 13138 sensor. It is a bit bigger than the one that was previously installed, so although you can use a full-depth O2 sensor socket (22mm) for removal, you cannot use it to install the replacement due to space limitations.

Final update/synopsis:

After replacing the O2 sensor and resetting the computer, I have driven over 400 miles and the Check Engine light has not since come back on. At this point, I believe it's safe to say this remedied the issue.

Grats this is just your other personality talking... your still crazy

Who in the hell just said that?

I know this is an old thread, but did the OP get his fixed when replacing just the O2 Sensor as I'm having the same issue just pop up on my new-to-me 2001 XJ 4.0 Auto.

Thanks.

I think he had to replace the O2 sensor because he killed it accidentally when the PB Blaster dripped on it...O2 sensors don't like oil, power steering fluid, ATF...pretty much any oil based chemical.... OR he replaced it to fix the problem and HAD to use PB Blaster to loosen the sensor to get it out.

Based on the first couple posts I believe he soaked the sensor in PB to get it out. Thanks for bumping this thread as I am having the same code pop up on my 2000.

I threw the same code in my '96 ZJ 2 weeks ago. My cat was 100000 miles old and gave up. After I got the new cat in I read the reader again and the rear O2 sensor was bad...only lasted me 203,000 miles, so I won't complain.

Fixed them both and away I went.