I got a new car the other week (!), and car dealers being what they are, the tank was nearly empty (had enough to go the thirty miles back to my place, then the fuel light came on.) So while filling it up, I noticed the inside of the gas cover said to use 91 octane or higher, and I was already halfway filling it up with 87 (it’s a 99 Passat, the 2.8 L V6 if that matters…) So I figured I’d suffer through this tank, and then just fill it up with the 91 next time I filled. Then the check engine light came on about…50 miles later. Could the two be related? Should I wait until after my next fill-up before I get it looked at?
Its probably just the gas cap…What i would do is disconnect your batter and reconnect it and see if the check light comes back on.
I’m 99% sure it’s not the gas cap, cause I had a check engine light problem with my old car (kept having misfiring cylinders,) and someone suggested the gas cap, so now I ALWAYS make sure it clicks several times.
But I will try the battery thing.
Take it to the dealer…the check engine light could be multitude of different problems…
Take it back to VW and let them sort it out.
Low octane gas can cause problems on VW’s, and could be responsible for the light coming on. Of course, the only way to know for sure if that’s relevant in this case is to read the trouble code memory. The light may go out after a certain number of consecutive engine starts and drive cycles (e.g., 50) in which the triggering condition is absent.
Persistent engine knock might set the CEL, and low octane gas could cause knocking.