My 997 turbo is tuned and I always run MS109 race fuel in it even though I am not running the race program just for safety reasons. I am at Harris Hill San Marcus track and run 10 hard laps in the car only with the spring sport button on but not the sport button because I do not need the extra power. I am doing a cool down run and get a check engine light. I have a small hand held programmer and reset the check engine light but forget what the code was. I slowely run the car on the track at slow speeds everything runs fine and then after a few laps start hammering the car again run an additonal 5-6 hard laps and everything is fine. Drive the car 40 miles home and no check engine light and car drives great. It would seem to me that if there was something really wrong with the 997 turbo the check engine light would come back on shortly after I reset it. I had a similiar issue 3000 miles ago and had the dealer check everything because the readout of the code was left bank lean. Checked all of the vacuum hoses and everything checked out and had no other issues until now. Seems weird that the check engine light happens when I am running it very slow at low RPMS. I was wondering if always running MS109 could be the culprit. I do it for safety but maybe the high octane produces some AFR numbers that occasionally blip the system. Any thoughts anyone. I will leave out the tuner because I plan to call him direct. I have to say the car is and ran the track fantastic and the power was incredible and felt great. I have 7,000 miles on the turbo and changed the oil 3 times and the air filter twice. I am a little bit annual about this.

 

any other mods other than tune? stock filter?

 

I have the AWE 750R kit. The car runs fantastic and cannot be more excited with the kit. I run VP racing fuel MS109 all of the time for safety reasons even though the car does not need it and because the car runs better with the fuel. I had a previous error code come on a year ago and it read left bank lean. I was running the car very softly at the time but had the 750 race fuel program on. I had MS109 in th car. At the time I cleared the code and the code never came back. I took to the car to the dealer because the original potential diagnosis was a vacuum hose leak. Checked all hoses everything looked good no more problems. Then I am at the track yesterday and ran the car very hard for ten lamps. I had the car on the regular 700 hp setting but I was running MS109 like I always do. After the tenth lamp I was running a cool down lap on presto check engine light. I had a hand held inexpensive code reader and clearer in the car and reset the code. I drove the car very softly at first and then harder and harder but no code. Drove the car 40 miles home and everything works great. Car is running fantastic. One of my thoughts is the constant us of MS109. I am not sure if anyone on this board runs only MS109 everyday. I do not think I have used premium unleaded fuel for at least a year. Any thoughts.

 

Where are you getting the fuel? Are you storing it yourself? Def. check with AWE and see if any other user has reported such a problem.

 

John, oxygenated race fuels like MS109 and Sunoco 104 can trip the secondary O2 sensors. I have seen it and it is nothing to worry about.

 

Eclou that is my thinking because the car is running fantastic and was a beast at the track. Every time the light when on on was barely on the gas and switching at 2000 rpm. I light to use the fuel because of the horsepower we both are using and the added safety.

 

Below is a Z06 my friend and I bought as an additional track car to car with our turbos. We put HRE wheels, Brembo and Eibach shocks. We also went with a 345mm rear. You need to drive it because it is different than
the 997 turbo and fun.

 

Jon's turbo ran great. I drove it and the check eng light did not come on for me, but maybe that had to do with the fact that the car liked all the hot laps I was putting it through

The C6Z06 is a completely different beast on the track and imo just as much fun to drive. I guess I had not given the vette the credit that it deserves running fast through the twisties.

 

friend here locally has one that was written up in GM High Performance magazine - exhaust, cam, and heads. The thing is a sick beast!

 

prolly just an 02 code or something... what exhaust/cats are you running? Doubt it's anything serious but should it come back.. next time jot down the P-code and let us know so we can all help