Drew707
Well-Known Member
So a bad cat can cause a loss of power and poor gas mileage?
so a bad cat can cause a loss of power and poor gas mileage?
so if i hollow out my cat will the problem go away? or would i lose even more backpressure?
If the cat.converter being blocked is the issue then the problem should go away...if its only one of the issues then the problem may persist.
As it is right now you are NOT loosing backpressure, there is actually too much of it since the exhaust gases cannot freely pass through the cat (due to it being possibly blocked)
Understand that if the cat.converter is rattling you WILL have to change it anyways if you want to pass smog/emissions. By hollowing out your current cat.converter you're just using it as a means to diagnose the problem.
If you can, try to get a used or at least an aftermarket one - that will save you hundreds. Hopefully a clogged cat is your issue, and hollowing it out will solve your problems. Don't forget to look into the spark plug defouler trick for your o2 sensor, so you do not throw a code, if emissions are necessary or CEL's are something you want to avoid.
My cat went to sh!t last spring, rattled, crap gas mileage and loss of power. I got a new one on eBay for around $120 shipped. Passed emissions with flying colors :jarred:

whats the spark plug defouler trick?
i cant find any cal state legal cats on ebay. there are some knock off magnaflow ones for 60$. but doesnt say anything about smog legal. and 1 real magnaflow one for 250$