Registered. it shouldn't throw any codes as long as you keep the O2 sensors hooked up. if you delete the cat entirely and do not hook up the O2 sensors, you will throw codes and run rich. you can delete the cat and weld in a test pipe for the O2 sensor.

What happens if I hollow out my catalytic converter?

Removing a catalytic converter will result, at most, in 5 HP in power improvement. However, hollowing out a catalytic converter will cause resonance problems. The symptom is most often seen as a hesitation, popping, or backfire at or about 3000-4000 RPM.

Will my check engine light come on if I hollow out my catalytic converter?

With the converter hollowed out, both 02 sensors read exactly the same. The computer will see that and turn on the check engine light. If the check engine light is on, you will fail the OBDII emission test.