The Stovebolt Site Forums The Shop Area The HiPo Shop catalytic converters / 02 sensors

i think that the guy may be talking about the 02 sensor that is positioned after the catalytic converter and not the one in the exhaust manifolds/headers. The one after the cat monitors the cats efficiency or ability to clean the exhaust. The computer monitors the post cat 02 sensor and compares the data to the pre cat 02 sensor(s) in the manifold(s). On some vehicles you can remove the cat and never have a code appear, but on others within a few driving cycles the code will appear. Ive even heard of people mounting the post cat 02 sensor outside the exhaust like on the frame and never having a problem. Otherwise removing the cat on a vehicle without a post cat 02 sensor should have no effect on the engine at all, besides a better flowing exhaust.


as a personal experience, my brother has a 94 Pontiac Trans-Am with a LT-1 and is currently running it without a Catalytic Converter. He has had no problems with it as there is no sensor after the cat. Now if his car was a new model and would have done the same thing its most likely the computer would be throwing a light. Another example is my daily driver, a 96 Pontiac Grand Am with the 2.4L I4. It has a sensor after the cat, and because the cat is so far gone, the light never goes off. Never had a problem passing yearly emission tests though.