Celica Forums General Discussion Exterior Catalytic converter and O2 sensors.

I was thinking of cuting off my stock cat and boring it out then welding it back on. Does anyone know if this will cause my check engine light to come on because of the sensors? And has anyone tried this

heard of it before. only 1 way to find out. but there's no way you'll ever pass an emmisions test w/o the cat.

Do you have to take an emmisions test? Im not sure but I have never heard of anyone i know going.

well fellas. You will not pass emissions and your CEL will come on. Don't 'bore' out the cat. Just get a Hi Flo one. They are carb approved and will not set off the light.

high flo cats only add like 1 hp...our stock cats are good enough. its not woth the $$$ IMO

dont mess with your cat. you could get cancer or some other disease. they are just full of bad stuff.

and dont take it off either, because then all of that bad stuff gets into the air and we all have to breathe it. yuck

For reals!!!!

I got a Hi Flo cat. Someone got a problem? JK guys.

For real, if you want one, then get one.

i've got a test pipe, no cat and no res that I can bolt up for the track.

It makes a big difference. Dropped me an average 1 tenth in 1/8 mile times and gained 1 mph in traps, thats with it bolted up to my trd alxe back exhaust.

unbolted/removed trd exhaust with testpipe I've gotten close to 2.5mph gains in 1/8 mile traps!!!!!

from 77's to 79's

CEL will come on, it wont hurt anything but the enviornment, so only run it at the track!