Chrysler 4881638AC Catalytic Converter

To replace the catalytic converter, the vehicle should be raised and securely placed on jackstands. The downstream oxygen sensor should be removed, and penetrating oil should be sprayed on the nuts and bolts before attempting to loosen them. The clamp behind the converter should be loosened, and the nuts and bolts attaching the catalyst to the exhaust manifold should be removed. The catalytic converter can then be separated from the exhaust system. When purchasing a new unit, it is important to ensure that it is identical to the old one. Before installation, the threads of the nuts and bolts should be coated with anti-seize compound, and the fasteners should be tightened securely.

To check for a restricted converter, you can use a vacuum gauge to diagnose the effect of a blocked exhaust on intake vacuum. By following the steps of opening the throttle until the engine speed is about 2000 rpm and then releasing the throttle quickly, you can determine if there is a restriction. If the gauge doesn't show a significant increase in reading or seems to momentarily hover around its highest reading before returning, it indicates a plugged exhaust system or converter.