How bad is it to drive on a bad Cat? I took the Z to Meineke for an oil change and I mentioned the sulfer smell I'm getting in the car at times. He tested the Cat and mentioned it was bad. I'm not looking to spend the 250 to replace it today. How long should I go without replacing it, a week, 1 mo, 3 months? I will definately attempt to replace as soon as I can. Also, would a Check Engine light come on if the Cat was bad?

 

well if you live in a state where they dont check emissions you could just cut the cat out and put in some straight pipe, otherwise i would get a new cat asap, its going to cause manifold gasket leaks if you dont, plus its probably robbing your fuel mileage and taking some horse power, now if you have a 96' + car you have o2 sensors after the cat that you will have to tune out or put o2 simulators on... it would be nice to know the basics about your car for further reference, most people put that stuff in the signature

 

Thanks man, I live in Az, so we do have emissions here. The car is a 95 Z28, M6, stock LT1. It does have Edelbrock Headers, Borla Exhaust, K&N Air Filter. I will definately try and replace it this upcoming week.

 

Are you sure the car isn't running rich for some reason and thats whats causing the converter to stink? What test did they run to determine it's bad?

 

Since you have a 95, there is no SES light if the cat is defective. That diagnostic was not added until OBD-II was introduced in the 96 models, and they added the after-cat O2 sensors to determine if the cats are present and working.

If the cat is simply not working, it will not harm the engine in any way. It just doesn't clean up the exhaust. If its starting to plug up, it will cause excessive backpressure on the engine, the power will be down, the headers will start to glow, etc. That's when you definitely have to replace it.

 

Thanks, as always for your help. As for the test to check the cat, I believe the tech was using a temperature gun. There was a big difference from the front of the cat to the rear of the cat? The car is running great, there is no signs of any issues besides the funky smell from time to time. I also had Meineke tighten and replace one of my headers bolts that was missing. I wonder if that was causing the funky smell, loose/missing header bolts?

 

If under certain conditions O2 was entering the exhaust from the leak the PCM would see it as lean and add fuel which could have caused the smell. When the shop did the test, did he say the temp was higher in front or back? Higher in front would indicate a plugged cat. Higher in back would be normal. Since you had the bolt replaced/tightened I'd wait and see if the smell returns

Brian

 

Header leaks cause it to run rich.... may have contributed to the smell.

 

The temperature gun stated that it was hotter at the front of the cat, towars the engine. It does sound like the cat is plugged and will look into replacing it asap. Yo Brian, what part of Nor Cal you from? I lived in good ol Pittsburg, Ca. through my teenage years.

 

Buy a universal cat on ebay for $50 and take it to a muffler shop and have them swap it in, should be like $50-$100. Afterwards, take your bad cat to the metal recyclers for $15.

 

Vacaville.

 

re :magnaflow catalytic converter

My garage has a pacesetter headerback, will the catco catalytic conv. could bolt on as well.

 

re : magnaflow catalytic converter

My mechanic owned the magnaflow system, will the bosal caddilac conver will fit it.