Q: My chevy venture is pulling up a po420 code but we can't seem to find out why ?

Diagnostic Trouble Code P0420 has many, many potential causes including a damaged muffler or leaks in the muffler, damaged exhaust manifold or leaks in the exhaust manifold, damaged exhaust pipe or exhaust pipe leaks, misfiring in the engine, oil contamination in catalytic converter, a faulty catalytic converter, a faulty engine coolant temperature sensor, faulty front oxygen sensor, faulty rear oxygen sensor, damaged oxygen sensor wiring, oxygen sensor wiring that is not properly connected, damaged oxygen sensor connectors, a fuel injector that is leaking, fuel pressure that is high, and other causes. The only way to determine which of these faults is the cause is through a diagnostic. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a check engine light diagnostic - code P0420 and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.