No the cat is just basically there with no sensors, so the ECM doesn't know if it's there or not...the LLY may be different, but I doubt it. Basically the only thing that happens when you take the cat off is less restriction and lower EGTs...doesn't sound bad to me...Mr. Mister said:Won't removing the cat set off the check engine light and screw with the computer?Ê I know that on gassers there is a pre and aÊpost catÊO2 sensor.Ê Wouldn't there also be that on the diesels.Ê If so it would set off the check engine light because the post cat O2 sensor would be reading high emissions.Ê And I would also be concerned that something else in the emission systemÊwould try and compensate for it, possibly hurting the motor.Ê What do you think?
dirty old man said:What duramaxes came with cat? Mine is a 2003, and if there's a catalytic converter under there, I have sure missed it. Is this a CA thing or what?