Engine Check

[Ernie50]

any one has any idea what is p0420 engine check light mean ????

[jsmith8918]

This may not be exactly right for your application as it is actually in the manual for the Toyota, but it could serve as a starting point if nothing else:

P0420:

System detected: Catalyst System Efficiency Below Threshold

Possible Trouble Areas:

1. 3-Way Cat. Converter Problem

2. Ophen/Short HO2S Circuit

3. HO2S Failure

Hope this helps.

[445187]

this may sound silly, but check you gas cap & be sure that it is tight, if it isn't or the seal is worn, it could cause the check engine light to come on...

[SKperformance]

If your cat is not functioning properly it is probably caused by something like carbon build up.

What gas are you using?

Also find a local motorvac or terra fuel place that does high pressure fuel injection cleaning.