Check engine light in 2006 Pontiac grand prix 6 cyl after check gas cap light.?

[ArthurP]

My check gas cap light came on and then check engine light afterwards the gas cap is fine no fuel leaks, no noticed reduced performance no unuasal sounds smell etc. What is the check engine light due to?

[none]

It will go off after a few "starts and stops". The check engine light will come on along with the gas cap light because the computer monitors the pressure in the tank to make sure no fuel vapor is leaking into the atmosphere. If it sees a leak, these lights will come on. Most of the time it is because the cap was left off after a fill-up. If this didn't happen, you might need to replace the cap. Your car being an 06, it should still have a warranty and the dealer will check it out for free. The first thing I would do though, is to make sure the gas cap is on tight. Good luck to ya...

[AmadorJ]

take to dealer possible gross evap leak causing both lamps to turn on.
will not effect the way the car runs so there is no hurry but seeing that light annoys anyone.(evaporative systems controls that fumes from gas so they dont escape into the atmosphere )

[MikeD]

i had that problem..the seal might be bad on your gas cap or you diddnt tighten it all the way...your auto parts store sells seals to replace and you can disconnect the battery for 20 min to reset it ,the light should go off.

[BrianD]

A loose gas cap will set both lights. You have to take it in to a garage and have the light checked and turned off.