My check engine light came on and code P0300 came up and I was told I needed new spark plugs and wires. I had those replaced and the car ran terrible so I took it back. They informed me that they had crossed the coil wires and fixed it. The light was out and the car ran fine...
2. VW/Audi standards on CAT fault codes is: a. Clear the fault code and use a factory-compatible scan tool to force the readiness monitors on the vehicle. b. If the fault code clears and the readiness monitors pass, send the vehicle on its way and when the fault code returns a secon...
Step 1 – Resolve Engine Trouble Codes The first step is to resolve any other codes that may have come up in addition to the P0420; especially troublesome is the P0300 series of cylinder misfire codes. A P0300 code could be related to something in the ignition (spark plug or coil), th...
The code P0420 - Catalyst Efficiency Below Threshold (Bank 1) means that there is a problem with the catalytic converter of the Bank 1. The code P0430 means the same fault for the Bank 2 catalytic converter in an engine with two cylinder banks (e.g., V6 or V8). The catalytic convert...