Hey, I gutted my cat and now my check engine light keeps coming on... I reset the ECU and the check engine light went off, but came back on... I remember seeing something that you can plug in to fool the o2 sensor but dumbass me didnt save the web page... please help

 

It's called an "oxyen sensor simulator" but you shouldn't have gutted your cat in the first place. You can find one in numerous places if you do a search for that phrase on yahoo.

Just remember that you're going to need a new cat if you want your car to pass emissions.