Back pressure test
Punch a hole in the appropriate position of the exhaust pipe at the front end of the catalytic converter, connect a pressure gauge, start the engine, and measure the exhaust back pressure at idle speed and 2500r/min respectively. If the exhaust back pressure does not exceed the engine regulation , it means that the catalyst carrier is not blocked.
If the exhaust back pressure exceeds the limit specified by the engine, the exhaust system at the rear end of the catalytic converter needs to be removed, and the above test is repeated. If the catalytic converter is blocked, the exhaust back pressure will still exceed the limit specified by the engine. value. If the exhaust back pressure drops, it means that there is a problem in the exhaust system downstream of the muffler or catalytic converter, and the broken catalyst carrier stays in the downstream exhaust system. Therefore, it is very necessary to first perform a visual inspection to confirm the integrity of the catalyst carrier. The faulty exhaust pipe, muffler and catalytic converter can also be judged by measuring the pressure loss before and after it.