To reach proper operating temperature, spend at least 20 minutes driving at highway speeds once a week. Don't let your car sit for weeks without being driven, and make sure you take a few long drives rather than only short trips. If you have to replace your catalytic converter, make sure it lasts as long as possible with these tips. Sometimes, the catalytic converter absolutely needs to be replaced (like if it's broken internally or melted down). Make Your Catalytic Converter Last Longer If the engine control module (ECM) detects a catalytic converter problem, it might record DTC P0420, defined as “Catalyst System Efficiency Below Threshold.” An illuminated check engine light or malfunction indicator lamp (CEL or MIL) with a catalytic converter diagnostic trouble code (DTC) is the most common catalytic converter problem indicator.

Failing the annual or semi-annual emissions test might also be linked to a failed catalytic converter.A rattling noise when starting the engine might indicate a broken catalyst.If the catalytic converter's housing is discolored or warped, there may be internal leakage or overheating.Ammonia (NH 3) odor may also indicate poor catalyst function. A sulfur or 'rotten egg' smell indicates the formation of hydrogen sulfide (H 2S), a likely sign of catalytic converter contamination.A clogged catalytic converter essentially 'suffocates' the engine, preventing it from 'exhaling' the exhaust. These issues could indicate a clogged catalytic converter, restricting the flow of exhaust out of the engine. Engine accelerates poorly or is hard to start.

1998 4 runner walker cat