Ok, I know you guys want the code, but I was just wondering about something else first. I disconnected both battery terminals and let it sit for 20 mins, reconnected, started it up and as soon as all the dash lights went away, the SES light stayed on. It never went off. If anything, what could fail and the computer would notice it right away? I know some components the computer won't notice right away until it has been driven.

My friend is coming over later this morning with his Snapon scanner. Should have a code by then.

 

Let us know what the codes are and we will work from there.

 

P0442 Evap small leak.

Cleared it. Now waiting for next couple of drives to see if it will come back.

 

It's not an absolutely conclusive code, but anytime mine has thrown it, the gas cap had not made a complete seal. Make sure it had clicked at least 3 times when you close it.

 

I did that this morning, at the same time not realizing that the truck needs to drive and get what 3 complete passing tests before it will clear out. ???

Well, we shall see in the next few days of driving.

 

It'll probably be back but may take 200 miles of driving, depending. If it does-report back and we'll all do our best to help! Jerry

 

I'll be watching this thread, I have been throwing the same code for a while, clear it every 200 miles or so.

 

Thanks guys for the support. I'll be posting back the second it comes back.

My friend that brought his Snapon over use to work at a GM dealer and seen this code a lot. Most of the time it was the valve above the spare tire. ??

 

Yeah, the EVAP Vent Valve. I had to replace mine on my old 2000 Bravada and the one on my uncle's 1999 S10.

 

Mike-I agree with Kyle and your buddy but...there are other things in the system-but the vent valve is(from my prospective) is the most 'popular' thing to fail. Your buds snap-on may be able to activate/de-activate this valve verifying something. good luck. JP[X(]