Is it possible to take catalytic converter off the exaust pipe and install just a pipe between the fittings were the catalytic goes, will the ECU take no notice of the O2 sensors(there are 2) and continue to work of the over sensors Of the engine.

One thing i just want a bit more horsepower of the engine, and when taking the car for MOT i just want to install the catalytic converter back for that time.

At this moment Iam getting code P0420 and I am sick tied of the engine light comming on, Me I live in finland and the light only comes on when it gets really cold outside, after clearing the dtm's the light does not come back on, only if it gets cold outside.

 

Even if you use a test pipe, the car's computer (PCM/ECM) would still look for the signal from the O2 sensor. Some people use a defouler at the rear O2 sensor.

 

Here is what I am going to try out. I am going to make a pipe were the cat fits(take the cat off), then I am going to plug the first O2 sensor with a bolt on the exaust pipe>>does anybody know what thread it is on the sensor? then I am going to just dissconnect both O2 sensors and see what happens.