# Is it the fuel or the fuel tank cap? Please help this newbie.



## JesseM (May 28, 2017)

Hello everyone, newbie here :wave: I have a 2004 VW Touareg (recently purchased) with 4.2L V8 engine. They opened a new gas station in my area where they sell E85 unleaded gasoline. The sticker next to the pump said this gas is ok for all cars 2001 and newer, so I put half a tank of E85 in the car. The following morning the yellow engine light came on. I suspected that it might be the E85 so I went back and filled up the rest of the tank with 89 unleaded gas. The yellow engine light did not go away for a full day so I took it to a mechanic closeby who found an EVAP code. The first thing he did was inspect the gas tank cap, and sure enough the seal was missing from the gas cap, so we put a new aftermarket cap on. He also cleared the code. 

The following morning the yellow engine light came on again. I took it to an Autozone and they found a code for the gas tank cap. *But I had just put a new gas cap on the tank*. Does anyone know what could be the more likely reason for this code? Could it be that I have a defective fuel tank cap, or is it more likely to be E85 that I put in the tank? I don't want to go buy a new cap only to find out that the yellow engine light stays on.

Any response will be greatly appreciated.


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