gregb091

My XJ has been throwing a P0432 code off and on for about a year now.. It's now idling rough and getting really bad mpg's (~9 mpg). I also believe the injectors are dumping in too much fuel because there is a lot of black soot accumulating around my tailpipe.

My plan is to replace the pre cats with the Walker part #52304 assembly, and also to replace all 4 02 sensors. My question is, is it possible to change the pre cat assembly without replacing the header too?

Any feedback on other possible solutions to my P0432 code would also be appreciated.

mdnov

That item attaches to your manifold. So you do not replace the manifold. You are also going to need part#53440 because you stated you have a 2001 Cherokee.

gregb091

Thanks for the reply.. could you please explain why I need that extra piece of pipe too? Wouldn't the #52304 bolt up directly to the existing pipes?

mdnov

I put the part number into a search engine and did some research.

gregb091

If you can find it would you mind posting the link where you read that? I wasn't able to find any info about needing that extra pipe

evan00xj

I just replaced mine. Fortunately i had a good friend of mine with a welder help me. Its a ***** to bold the cats up to the header. Yes there are 4 02 sensors. Take your time with it. My old pre cats were shot as you can see here

gregb091

Yeah... I'm leaning towards buying the parts from rock auto and taking it to an exhaust shop to have them do the install. You're saying that you weren't able to get the new pre cats to bolt up with the header, so your friend cut and welded it instead?

evan00xj

Well to give you a complete overview, the previous owner installed a banks torque tube header on it. My cats were clogged bc of the high zinc phosphorus content in the racing oil he used for the stroker. So basically i just replaced the front cats (all one piece). They bolted right up to the header, then bolted up to the factory flange on front exhaust pipe. It has all 2.5 piping. I got the front cats from performance curve. Then i threw a banks monster muffler on there (straight through ) sounds good, great flow, zero drone.

gregb091

Thanks for the pics, very helpful.. from the looks of it, I'll need to replace my pre cat assembly and have a new flange welded onto the front exhaust pipe where it meets the pre cats.. hopefully I can find an exhaust shop nearby that won't charge me something ridiculous.

evan00xj

Good luck to ya, the price on performance curve and rock auto are like the same. Its funny actually because the previous owner deleted the factory flange. In order to ensure proper OEM fitting i had to go to the jy and sawzall the flange piece off a 01 lol. Im very fortunate my friend is a welding guru. I would make sure to replace all 4 02 sensors as well. After the complete over my jeep was running ALOT better. I am always glad to share knowledge man, because i couldnt really find any info when i knew i had to do mine.

evan00xj

**overhaul

gregb091

Yeah, if the new cats and 02's get my jeep running better and my mileage back up from 9 mpg it'll be worth it.. I'm pretty sure this is where my problem is since all the signs lead to bad cat/02's (P0432 code, bad mpg, running rough, tons of soot at the tailpipe).. fingers crossed and thanks again for the replys.

Redsnake

Bumping this thread to see if the OP got this issue resolved? Similar issues on my '01 XJ. Just looking for others experience...