Why would my "service engine soon" for my "01 silverado stay on ,even after a new gas cap?

Answer 1

I HAD AN 04 SILVERADO AND I FORGOT TOTIGHTEN THE GAS CAP ALL THE WAY BUT DIDNT REALIZE IT THE NEXT DAY MY SERVICE ENGINE LIGHT CAME ON AND A BUDDY TOLD ME TO CHECK THE GAS CAP I DID AND IT WAS LOOSE SO I TIGHTENED IT AND THE LIGHT WAS STILL ON SO I TOOK IT TO CHEVY AND THEY HAD TO TAKE THE CODE OUT WITH THERE COMPUTER AND IT WAS BECAUSE OF THE GAS CAP

Answer 2

Who told you that a new gas cap was going to fix the problem. If the freeze frame data stored in the pcm showed a large evap leak then the problem could be the gas cap and after replacing the gas cap and the light didn't reset in three good trips then you have another evap leak somewhere. everybody wants to reset the pcm to just shut the light off but doing this erases all the information stored in the pcm that was stored there to reduce diagnostic time. the check engine light is a money saver not a money maker obviously most of these people don't know what there doing.

Answer 3

Sometimes it does take awhile for the check engine light to turn off after the problem is fixed, if it wasn't reset by the dealer. I had mine come on after I left my gas cap off and it took several shutoff and starts off my engine before the light went out. If it does stay on you may want to have a mechanic plug it in to see if there is possibly something else wrong with your truck.

Answer 4

Take to a Mechanic and have him scan the ECM. The problem may have nothing to do with gas cap, such as an intake leak, common on these engines. They now offer the complete upper intake in the aftermarket, that's how common they are to fail.. They are also a lot cheaper aftermarket...

Answer 5

You may need an oil change,plugs,plug wires,or some of your filters may be clogged and need changed.What made you think a new gas cap would fix the problem?A gas cap has nothing to do w/the engine.BEST ADVISE=take it and have it proffesionally serviced!

Answer 6

The light on my '96 Merc stays on after being serviced. Several mechanics have told me the same thing- it's burning too lean- meaning the gas is not so good. Funny. It started right after the "war" started and gas prices jumped. Coincidence?!?

Answer 7

There might be another problem or there might be no problem, I have had the service engine light go on for bad spark plugs and for somewhat clogged fuel filters. I had to take the car to a mechanic to get the lights reset.

I think they are a rip off to generate more revenue for the mechanic. If we fix a problem, the light should go off.

Answer 8

There is a fault in the engine management and the computer has logged a fault code. You need a diagnostic scan to access the fault codes and then fix the problem. Jules, Auto tech/lecturer. Australia.

Answer 9

Because there is something that needs servicing other than your gas cap, my dear :-)

Go get it checked out. Hopefully it will be something simple and inexpensive.
Last time mine came on, it was because of an oxygen sensor....I got lucky - it only cost me $75.

Good luck with your truck!

Answer 10

Take it to an Advanced Auto Parts or someplace that offers one of those little diagnostic machines that hooks up to your fuse box. The display will show you exactly what needs to be done. If that doesn't do the trick, it may be a faulty sensor. Perhaps it's time for a tune-up (refer to Owner's Manual).