c4vetteontop

Hi, i've got my cats removed on my 98 vette and at times the check engine light will come on and the car seems to run differnt. (in first its weird). But when its off the car runs fine.
What can i do to fix this problem.
I think it tricks up the computer and makes the car run differnt.
Whats wrong and the things i can do to fix it (make sure the check engine light doesnt come on)

99 vett babycar

what codes are you getting ?? It's not the check engine light that's making it run different, it's whatever is causing the check engine light to come on . Can'tell cause without some code info.

RPOZ4Z

the computer is not "seeing" a normal condition due to the fact that you removed the cats.

you probably need O2 simulators.

vettes4fun

Bill Curlee

Here is an excellent web sie for codes:

This is the absolute best C5 Code web site!!!

http://www.corvettedoctor.com/Codes_Page.htm


If you just removed the CATS, your PCM is is detecting CAT efficiency problems! The rear O2 sensors are most likely setting the codes but there could be other issues!!

Read and post the codes. Clear them and repost the results if any come back on when the problem is detected.

Bill C

SR71

you are probably running in open loop when the check engine light is on...certain o2 codes will cause the car to go into open loop. meaning the fueling is handled from the map in the computer only and not fine tuned by the o2 sensors. my car does this when it is time to change the sensors. I go through a lot of sensors since my car has a lopey cam and runs rich under boost. I can clear the codes and the car will run in closed loop until the code pops up again.