Co-Authored By:
In most states, hollowing out a catalytic converter is not only difficult, but also illegal. There is no good reason why you should need to hollow it out, and doing so can land you in a lot of legal trouble. The best solution is to keep the catalytic converter as it is and try and seek another solution to your problem.
Hereof, can you replace catalytic converter with a straight pipe?
Before replacing your expensive catalytic converter, make sure it is the culprit by replacing it temporarily with a straight pipe, sometimes called a test pipe. If your car runs properly with the test pipe in place, your catalytic converter will need to be replaced soon.
Beside this, can I unclog my catalytic converter?
To some extent, a clogged catalytic converter can somehow unclog itself. However, do not expect that it would be as clean as a whistle compared to using a cleaning solution to get rid of all the debris that has accumulated within the engine system, particularly after using the vehicle for a long time.
A cat will pose no significant restriction. There is no gain in performance. If you drill holes into it you fool the oxygen sensors into thinking the mixture is lean. That will tell the ECU to command more fuel and it will skew fuel trims.