BE CAREFUL NOT TO RUN YOUR CAR HARD WITHOUT THE GASCAP ON. I made the mistake of leaving the gascap off after fueling some hi-test fuel. I thought the meth failed because I was running 13.5-13.6 a/f in 3rd gear for a few seconds and could not figure out why!!! The fuel system on the 2005's do not have a flapper door in the gas filler. The fuel system needs to be pressurized! AFR are totally thrown off with the cap off and it wouldn't surprise me to hear of detonated motors due to this type of accident.

Blew me away and had to share this interesting and scary news... To the best of my knowledge I believe only the 2005+ do not have a gas door flapper.

You will also notice that the car has a very difficult time idleing with the cap off and has even stalled on me once while fueling. Yes, I'm one of those fire code ignoring guys that sacrifices fire safety for turbo bearing longevity.

 

That flapper is not pressure tight on any car. Just a heads up, my 03 did not have that flapper either.

Keith

 

It is understood. The flapper allows enough pressure to keep the motor from near stalling however. The main point is that if it is unsealed, afr's are affected in a potentially damaging way.

 

you should see a service engine soon light if you dont have the cap on

 

How did you leave the cap off?? its attached to the door and you wouldn't be able to close the door because the gas gap would be haning down, wtf???

 

Fueling race fuel and filling meth tank. Adjusting safc, just overlooked it. It was hanging... Door open.

 

I've pumped gas a couple times before the turbo timer turned off the engine and it wanted to stall as soon as I started pumping but did not stall when I opened the fuel cap.

 

Did that same thing once. Scared the **** out of me when I heard it, so now I just wait until the tt shuts off