Looking for ideas. I am getting the check engine light for evap system.

Here is the history. '97 1500, 360/auto 4x4, 65,000. Plenum is fixed, tune up done.

A couple months ago the light came on. I replaced the gas cap thinking that might be it. Cleared code, light came back 2 days later.

Took it in. Charcoal canister was shot and sent carbon throught the line. Replaced line and installed new canister.

Next week light came on again. Replaced purge solenoid.

Light remained OFF for about a month and 2000 miles.

Light came back on again, same code. Lines have been gone over to make sure they are secured and all seem to be in good shape.

The truck runs great and gets good mileage. My mecahnic says, "Just drive it, it won't hurt anything". He's probably right, but with the light ON all the time I will never know if I have another problem brewing.

What else could it possibly be? Did I miss something?

 

Maybe charcoal in the lines?

 

my mom's caravan did that. it was the gascap, we replaced it. a month later it came back on, and it was the gas cap. just a thought

 

So, maybe just get another gas cap? Is there one brand better than another?

 

See if you can exchange the gas cap as being faulty and see if the new one fixes it sounds like you could have gotten a bad cap

 

if gas cap isnt the solution, look into ALL the evap lines....its also possible the egr tube could be plugged with carbon...

 

That is completly possible cuz i bought a kegger on here for a less chance of a huge down time, mine isnt egr the kegger was, Well the end of the egr tube in the kegger was FULL of carbon. Like i cut it out and held up to light and couldnt see threw at all. No light... lol. So that could be it...

 

i know you experts are gonna flame me out for this and say something has to be wrong and i don't disagree but these damn check engine lights are very finicky.

Mine used to come on in my 96 every few months or so, and would stay on for about a week then go away for literally MONTHS at a time. and it would do it almost like clock work. I never took it in to get checked because it was always gone buy the time i was able to take it in. If it came on every week i would so something, but the down time in between it coming on was so long that it just didn't seem to matter.

Just from reading your post i can see its a different issue for you but im throwing in my 2 cents.