I have a 97 f1 with an lt1/ ported & polished heads/catback/cai/1.6 roller rockers/ and ever since I pulled the car out of storage it threw up a check engine light. It ran fine and I figured it was because I uninstalled the battery for storage. About a week later one of the coil packs went out on it which I then replaced. When I took it for emissions testing it threw out a catalytic converter code and failed, as it apparently wasnt burning enough fuel but I have been getting decent gas mileage with it. This brought me to think that maybe when the coil pack went out on it awhile ago that it didnt burn some of the fuel which then put up the check engine light. I had the code erased off of the car and the light stayed off for a good 15 miles of driving then popped back on, the same code also. So now apparently the problem is a bad cat. I'm wondering if theres a way to gut out my cats and put some o2 sensor blocks on my f1 while being able to pass emissions at the same time or am I stuck with replacing the cat?? All help is appreciated!

 

Fist of all make sure the engine is in a good state of tone and that the O2 sensors are working properly. Then if the cat still showws bad efficiency, go ahead and replace the cat with a high flow unit, and keep the car legal. If you add the cost of gutting the cats, installing dummy downstream O2 sensors to keep the PCM happy, the price difference compared to replacing the cats wouldn't be that much, and your car will pass inspection. You can get Dynomax high flow cats for $54 universal fit or $ 97 direct replacemnt from Summit

 

thanks a bunch! I was starting to think it was a better way to run it legal, especially being in college and whatnot. Thanks for the info and prices I'll for sure have to check them out