Mopar 52101251AC Exhaust Converter

The easiest way to check for a restricted converter is to use a vacuum gauge to diagnose the effect of a blocked exhaust on intake vacuum. Connect a vacuum gauge to an intake manifold vacuum source. Warm the engine to operating temperature, place the transmission in park (automatic) or neutral (manual) and apply the parking brake. Note and record the vacuum reading at idle. Open the throttle until the engine speed is about 2000 rpm. Release the throttle quickly and record the vacuum reading. Perform the test three more times, recording the reading after each test. If the reading after the fourth test is more than one in-Hg lower than the reading recorded at idle, the catalytic converter, muffler or exhaust pipes may be plugged or restricted.