i have a 2k1 GSr and have greddy headers, exhaust and a high flow random tech cat. I had to get a new cat b/c the 2k1 have a different cat then 2k. Well anyway after having it on for a month my engine light came on and got a code of 67, which is a catalyst effeciency. SO i took that cat of and put my friends 96 gsr cat and after a 100 miles the engine light came on and it was the same code. Can any help me out and fix this probably?

 

I had the same problem with my carsound cat except my cel came on after just a couple of days. I've heard people say it has come on after several months. Anyway, it's not a big deal because your car will still run just fine, meaning it will not be running in limp mode.

 

it is because of the OBD II which has more sensors and restrictions than the older OBDs ...I got my piping done and exhaust put on yesterday and I wanted to get a testpipe or a carsound cat, but I didn't due to this reason. I know there are simulators that prevent the CEL from coming on now. And the guy that did piping said Carsound is going to make OBD II cats in a couple of months.

 

what's carsounds webpage and where can I get one b/c i hate havinb my engine light on.