[lrzmsr]

Hello. I'm new to this forum. It seems like one of the better ones. I have a 97' cherokee with 138K on it. I recently installed a Dynomax cat back sytem with a new magnaflow catalytic converter. After installing everything, my jeep started running really crappy. It starts fine, and will run fine for a few minutes. I took it for a test ride and it ran great for the first five minutes, then it wouldn't run right. It loses power and bucks around almost like its missing or something. It will also make popping sounds through all of this. I replaced the O2 sensor after the cat, cleand the throttle body really well, and also disconnected the battery for a few minutes(maybe thinking the computer needed to reset itself). None of this seemed to work. Anyone have any other suggestions?

[tjwalker]

Probably no relationship to the exhaust work you performed. Have you seen a check engine light recently or scanned your computer for any stored codes? Driveability problems always are a good time to review basic tuneup status. When is the last time your plugs, distributor cap, rotor and plug wires were changed? If questionable, swap in new parts. Simple things first. You may also want to consider a fuel pressure test by installing a pressure gauge on the schrader valve of the fuel rail.

Good luck and let us know what you find out.

[Dannyboy18]

You could have clogged a sensor when cleaning the TB. I'm blanking out since I forget what it was, but I am guessing this could be your problem. When mine was running rough, it was my TPS going out; no CEL or anything. Still, I cleaned the TB and it ran 'better,' but still messed up.

You can't rule out BAD LUCK. Honestly, about a month ago I was in STL and my XJ's radiator hoses decided to start leaking RIIIGHT before my 2-hour commute back to college... When I go to pick it UP from Dobb's on Sunday (yes I know, don't start, it was the only place open on Saturdays...), it started rough, threw a CEL and had a bad misfire...

OF COURSE I blame Dobb's initially, but then I thought about it and it couldn't have been them judging by the work that was done. Long store short, something in one of the fuel injectors (I think cylinder #1) had to be rewired and that's what was causing the CEL.

I'm placing my bets on a sensor of some sort.

[Crystalship1]

IMHO, You need to do an ECM reset after all of those changes. Disconnect a battery cable, turn on the headlights, wait 10-15 min., turn lights off, re-connect battery and then DRIVE for 20-30 min. (Just idling won't allow the ECM to re-learn). That's where I would start.

Good Luck!!

[lrzmsr]

thanks for the responses. i installed a new CPS and that didn't help anything. Before installing it, the check engine light was not on. I installed the CPS, it acted the same way, and now the check engine light is on. Is there anyway to find the code for whats wrong, or do i need to take it somewhere to get it read?

[tjwalker]

Take it in and let them scan for codes. Some of the big box shops like Auto Zone and Advance will do this for free in the hopes that you will buy any needed parts from them. Otherwise, this is something any shop can do for a minimal charge. Post back what code(s) come up....