[gnarjunkie]

Hey all,

Trying to track down a few seemingly connected issues with our 2017 BRZ.

My GF and I were co-driving at the last autox we did and noticed near the end of the day that the car had a faint fuel smell sitting in grid. It seemed to get stronger over time. We looked all over and could not see any leak inside or outside (track car, gutted interior, easy to see everything). The smell was hard to smell inside the car even with my head inside the back right over the fuel tank, tough to smell from under the car, and only really noticeable at the rear passenger wheel well area. Fuel cap was tight.

At the same time, the car also threw a P0171 code (AFR sensor issue, system too lean). It's worth noting the car was on the fuel light and had very very little fuel in it at the time.

We filled it up and let it sit for a bit during the 2nd run group, then went back and looked it over throughly. Couldn't notice any smell at all.

The smell came back at the end of the hour long drive home. Faint fuel smell that was noticeable in the garage after it had been parked. The code did not return. Since then I've driven it for another 45-50 minutes, didn't notice the smell while driving, but faintly noticed it after driving when it was in the garage. Still no code.

Car is tuned on Ecutek so we were able to datalog... AFRs look completely fine but fuel trims seem a bit off. Seeing about -8 to -10 LTFT. That's the only thing I can see that is possibly off. Can't find any obvious exhaust or vacuum leaks, though I haven't gone too deep into testing for that yet.

Any thoughts?