Giley's Jeep
New member
I live in a county where there is no smog regulations. Wise idea to remove converter to gain more performance or bad idea. And what effect, if any, if O2 sensors are left in place or removed?
If you remove the cat it will definitely mess up the downstream O2 sensors, and it will mess with the fuel mixture making it run rich. When it runs rich all the time it has an effect of "scrubbing" the lubricating oil off of the cylinder walls, which wears them out quickly. I tried this on an old Mazda pickup when I was in high school. Taking the cat off ruined the motor.