My XJ's cat convert is a rattling...magnaflow cat ???'s

[Thayer]

i'll post this here instead of starting a new thread. I have a loud rattle coming from either the cat or the muffle. The weird part is, it only happens when its cold out, lets say under 50*. In the warm weather I hear nothing.

Any ideas?

Heat shield spot welded to the top of the cat may have rusted loose.

 

[XJumpmaster]

Yeah, I'm not doing anything unless I fail!

 

[pma4x4]

In my 93 ZJ 4.0 I changed over to a Magnaflow cat and Flowmaster muffler Delta 50 Series. From before the cat and back was 2.5" I am not sure if there was a real gain. but throttle response was a bit better and it climbed in RPMs easier. I plan on doing same cat and muffler for my 96 XJ

 

[nightkrawler]

just fyi chrysler released a recall for xj's zj's and tj's to inspect cat converters and reprogram computers in affected vehicles. see yur local dealerseace:

 

[XJCreeper]

Both the 2001 I have now and the 2000 I used to have did not have a O2 after the cat. I have an O2 sensor on each bank of the exhaust manifold (header) just after teh pre-cats. So, 2 O2 sensors total. Maybe there was a change somewhere in the later model years???? It is OBD-II.

Did all OBD-II years have pre-cats on the exhaust manifold? Maybe they made the switch in O2 locations when they included the pre-cats in the emmissions system?

Some XJ's come with an 02 after a cat, others do not. Depends on the state or area the XJ was sold into. Some states/areas have stricter air quality standards and require the second 02 sensor to ensure the cat is doing it's job. My wifes WJ has 2 cats, an upstream and downstrean 02 sensor on each for a total of 4 02 sensors.

 

[VDoubleUVR6]

just fyi chrysler released a recall for xj's zj's and tj's to inspect cat converters and reprogram computers in affected vehicles. see yur local dealerseace:

I dont know about all Xj, ZJ and TJ's...I went to Jeeps website and ran my XJ's VIN through recall checker thing and my XJ had 0 pending recals.

Some XJ's come with an 02 after a cat, others do not. Depends on the state or area the XJ was sold into. Some states/areas have stricter air quality standards and require the second 02 sensor to ensure the cat is doing it's job. My wifes WJ has 2 cats, an upstream and downstrean 02 sensor on each for a total of 4 02 sensors.

WOW...is it a V8? If so then that makes sense...one cat for each bank on cylinders.

 

[XJCreeper]

I dont know about all Xj, ZJ and TJ's...I went to Jeeps website and ran my XJ's VIN through recall checker thing and my XJ had 0 pending recals.



WOW...is it a V8? If so then that makes sense...one cat for each bank on cylinders.

Nope it's a 4.0L HO. Those cats come right off the exhaust manifold before the collector and are packed tightly together. Replacing one or both of them would hurt the pocket book bad.

 

[RenegadeStang]

Anybody know what the inlet/outlet sizes are for the Magnaflow MPE-23226?

 

[zfinger]

Re: Cats

...and a disposel fee for the old one (cat)...

Haha, scrap yards are paying like $70 each for them up here, I just saw an article in the paper about people stealing them off cars in parkinglots and selling them as scrap. Looks like your shop is making out twice.

I used a Magnaflow highflow universal I got off some website for $55 and had that put in with a Flowmaster 50 Series. The Exhaust shop had no problem making the shorter cat fit. I cant remember if it was the Jeep or my 240sx now (they both have the same highflow) but they even cut and welded a bung in for the 02 sensor.