So I have a 2001 ls. It has been shuttering when i drive and there is a clanking from the cat and a whistling noise also (broken seal when tried to unbolt it). But my car is also throwing up a code for a bad o2 sensor 1 bank 1 which is before the cat. I am also getting a code for a cylinder 4 misfire which i changed the spark plug and the plug wire. My car will shutter as if the gas gets cut off then comes right back but after about 20 min or so it will smooth out. If I floor it it will not shutter but will max at about 3500-4000 rpms. So i was wondering if anybody knew where to even star and the best way to go about this problem.

 

You may have a clogged cat if your not getting high rpms & theres a noise coming from it prob means the material broke inside mine done the same id start there if anything

 

yep clogged cat lol :p
or at least get that checked out first

 

most local exhaust shops should be able to check your cat for you, also if you run for a while and it's glowing under the car (from heat) that's a sign of a bat cat.

a cat that goes to the bathroom everywhere but it's litterbox is also a sign of a bad cat, but that's a completely different story

 

 

Yeah well they were saying it was $25 to check the cat and ifi its bad $247 but i live in Florida where there is not any emissions testing so I was thinking of cutting off the cat all together and going with a straight pipe. Do you think the misfire would have blown out the cat and break another o2 sensor or would that be caused by the bad cat?

 

I wouldn't even consider that then if they're going to charge that much. go to ZZP and get a catted downpipe, it'll save you money and gain you some power. The code is going out because the cat is bad, since it's clogged, the 02 isn't reading correctly.

ZZPerformance - ZZP Downpipes #

there's the link to the downpipe. If you cut the cat out you will still throw that code until you tune it out or get a dongle that will make the pcm think that there's a cat there.

I think your best bet either way is to get the downpipe.

 

Thats alot better of a price I didn't even think of that thanks.

 

no problem

 

Would the bad cat cause the car to run rich?