austinpatton

can anyone tell me some symptoms of an exhaust leak. Under acceleration I hear a hissing sound, my engine seems to lack power (I have to push the pedal to the floor for my car to pick up speed) and my tailpipe vibrates so bad I can feel and hear it through the floor. BTW I have a 2000 Jeep cherokee sport 4.0 6 cylinder.

Thanks
Austin

COSXJFAN

Could be an exhaust leak, but that doesn't explain your lack of power. A leak will cause a power loss, but not as extreme as what you've described. I would have the cat checked out. It may have come apart internally, and be blocking the exhaust flow, that would explain your lack of power. HTH!!

austinpatton

I had my spark plugs changed the other day and I had the guy at tuffy check my cat and his computer told him it was fine. Any other suggestions? Is it possible his computer misread the cat? My car has 151,000 miles on it with the original cat.

COSXJFAN

I have never known a computer to be able to test a cat, but I'm not a trained wrench, and could be mistaken. If it is still "converting", then his computer would tell him it's fine, but if it has fallen apart inside it could be blocking exhaust flow, and still be "converting". I'm just saying that it would explain both of the issues that you described, and would be worth looking into IMHO.

okcjeeper

I am with COS on this one. No way a computer can tell if a cat has bloggage just that it's converting and nothing more. Get a hammer and tap it and see if it rattles at all, now not a sure fire fix if it does rattle it's bad for sure. Now when did this start happening? Was anything changed just before it happened? Based on what you said about it rattling so bad you can hear and feel it sounds to me like blockage.

Mattpar

give your cat a punch and see if you can hear anything rattle inside it. It will sounds like a bunch of marbles are in there it the honey comb cat material has broken into chunks. The one on my 95 grand sounds horrible, tin can full of marbles, but it still drives fine,...

austinpatton

I'll give that try, thanks guys. And this has happened since I bought the Jeep two months ago. While were on the subject whats the best cat I can buy? Do I want the kind that bolts on or the kind that needs to be welded? Also why do some cats claim to be direct fit when they still need to be welded.

Thanks,
Austin

COSXJFAN

All cats have to be welded, it's a mandate from the feds I think. Buy a high flow cat from a reputable company, and you'll be fine for a long time!! HTH!!

okcjeeper

I bought a Magnaflo high flow direct fit converter..When it's installed I will tell you how I like it. Basically get a high flow converter. Mine cost $99 not sure what one for a 2000 will run.

okcjeeper

Direct fit means they bolts to the s-pipe factory mount. You have a mount that is basically square coming off the s-pipe that has 4 bolts and uses a gasket.

austinpatton

Also don't know if this helps or not but when I accelerate there is sometimes a jump/jerk.

Metmknice

Possibly fuel pump

jd4x426

check for vacum leaks if you're hearing hissing it could be a vacum leak