Think my cat's gonna die

[6spdYJ]

Anyone experience this... I just put gas in and drove 25 miles(ish). As I came to a stop, the motor stared to idle rough and stumbled at partial throttle. I talked with a buddy who had his cat go bad in his TJ and he described this exact symptom. The next day, I tried a short full throttle blast and it sounded fine, but the power was a bit less.

Today, as I was driving at a steady 40mph, there was a BANG from the passenger side of the rig so loud, my ears were ringing. The motor didn't stumble at all. I didn't feel any drivetrain jerking. Nothing but just BANG. The best way I can describe it is like somebody shot the passenger door with a rock from a slingshot. It was that metallic but LOUD. Thoughts?

[Kodiak Spirit]

well, a cat for a jeep is cheep, so just run over to a muffler shop and have them burn one in. Go with a high flow type and you might even see a few HP gain, if you want to get fancy throw a nice magnaflow muffler in there (or some other fancy high flow number) If your 92 has never needed this work done, and you have the original stuff on there, dude, it's time.

I have Detroit lockers, so any bangin' I hear I just shrug off...

[aw12345]

The easiest way to figure out if the cat is bad is loosen the bolts that hold the exhaust pipe to the manifold, leave the pipe attached but with a gap and take it for a drive. If the problem largely disappears you know what to do. This will most likely turn on the check engine light though, but when everything is back together and working as it should this will correct it self after some driving

[6spdYJ]

I can get a magnaflow for $145 delivered. How much (ballpark0 would I be looking at in a shop installed. I do all my own stunts, so I have no clue what's reasonable.

[Lumpy Grits]

Hi, check to make sure it's NOT your O2 senser(sp).
Guess how I know this....
Respectfully,
LG

[6spdYJ]

Just replaced the O2 & header. The bang definitely came from the cat's neighborhood.

[RAT]

If your cat dies, bar-b-que him!Them thar are some tasty critters...

[chris142]

On 01-01-09 Ca passed new laws regarding aftermarket replacement cats. You cant just go to a muffler shop and have a cat installed for $129 any more.

Depending on the year of the car a replacement cat can run over $1000. If the aftermarket does not supply a cat that meets the new C.A.R.B regs then the new one must come from the dealer.


http://www.arb.ca.gov/msprog/aftermk...ftermktcat.htm

http://www.arb.ca.gov/msprog/aftermk...xemptcat09.pdf

My friends Subaru needs 2 new cats. They are $600 each my cost.

[chris142]

If your not throwing a po420 code your cat is probly ok. Assuming that you have OBD2.

[6spdYJ]

92 had OBD I and only has one sensor before the cat. Check the Magnaflow website for California legal cat's. The 39005 IS approved. Oddly enough, it's the cheapest I've found. I have seen cat's that say C.A.R.B. approved - Not California Legal... Carolina Air Resources Board????????

[Kodiak Spirit]

:hijack: If it wasn't for you MJR people I would be so outta this California! all it is is a state of confusion and frustration!!!!
The CARB thing is gonna kill the state, do you realize how much CO2 a brewery releases into the air? we are gonna loose all our Brewpubs! goodbye Oggie's!

[Jeeperator]

What's funny is in my 1997 jeep tj the new cat I put on ate itself up in less than 2 years. They took it off and it was completly Hollow inside(this is why it wouldnt pass smog) But it never set a check engine light to let me know it wasnt working so why is there a 2nd o2 sensors if it doesnt do anything.

[Mtbikbob]

Always carry a cps with you.... they are crazy critters that do funny things as well and an Achilles heel for a jeep.

[Guest]

www.PerformancePeddler.com has some good prices on cats and mufflers.. Been buying from him for over 7yrs.

The carb stamp on the cat went into effect last year or year before? It's just a way California gets money. There is no way the smog check knows when you placed it on (if it has a CARB label or not on it). The difference in price is only $50 or so though.

I had two trucks that actually passed (Nissan and Jeep) and the cat was destroyed! Had low power, it had just passed smog. Local shop said the cat might be bad even though it passed smog. He was right. So, for it not to set off the OBD I "CEL" doesn't surprise me.

[Jeeperator]

Always carry a cps with you.... they are crazy critters that do funny things as well and an Achilles heel for a jeep.

What kind of funny things? I do have a miss at idle I wonder if that has any thing to do with it.