that you can easily access the converter. using a drill, bore a hole about ¼ of an inch big in the pipe’s exhaust, just right in the back of the catalytic converter. attach a pressure gauge to the hole. start the car and take a reading on the pressure gauge. a low pressure reading at the back of the catalytic converter is not something to worry about. a high pressure reading is—and it is usually also a signal for you to change your catalytic converter.
check also the pressure in front of the catalytic converter. the procedure is the same as in checking for the pressure in the back of the 