Tech question: fault codes and CEL/VSC group lights

[Hardin66]

Fault diagnosis question: I have the pretty standard CEL, TRAC off, VSC off, anti-skid light issue on my 2006 GX470. Codes are P2401 – Evaporative emission (EVAP) leak detection pump, control – circuit low, P0430 – Catalytic converter system, bank 2 -efficiency below threshold, P2402 – Evaporative emission (EVAP) leak detection pump, control – circuit high, and P2419 – Evaporative emission (EVAP) switching valve – circuit low. Here are the conditions though; they only come on every few days on a cold start, they clear immediately and don't return for a few days when I erase them with the code reader, and the vehicle drives completely normally either way. I've replaced the gas cap. New evap cannister about 25k ago, and previous owner brought it in a few times for this with no resolution because they couldn't duplicate the malfunction at the shop. Does that set of parameters indicate some particular diagnosis for any of you experts? Thanks!

 

[jiggletits]

You won't find many "Experts" here. Mostly guys wanting bigger tires.

Wish I had some advice. I have techstream and have been chasing down VCS OFF and VSC TRAC light issue for a long time. No one seems to respond to the threads with any good advice.

As a next step, I would suggest getting techstream and learning how to use it then run your own diagnostics.

 

[Hardin66]

I maybe made it too complicated and un-fun. I'm really just trying to determine if the intermittent failure indicates something specific. If it was really leaking or one of the valves was failed it would fail every time I would think. Anyway...thanks!