My cars Service engine light only flashes if I rev the car in neutral or while the clutch is engaged. I can make it do it 90% of the time. The car will not flash the Service engine light once if the car is under load or WOT. HKS 272 cams, bolt ons, evo 9 turbo, injectors, fuel pump, EWG. The car has only thrown the code "turbo charger over boost condition" and the car runs and drives great. My AFR reads 19.5 ish at idle. Around 15.00 at mellow driving speed and under 12.00 at WOT. Is this Phantom knock? False feed back? Why does this light flash if the car is not under load? Do I need to worry or not? Thanks

 

I bet it's the CEL on knock feature enabled in your rom, it's likely phantom knock. But you AFR number sound lean, what fuel are you using?

 

I'm using 90 octane up here in Alaska

 

Yeah foxboat I believe it is the knock feature but the real question is what is causing this? Like I said we are using 90 octane up here in Ak.

 

I wouldn't worry about the stationery flash CEL, but your AFR is lean, or your Lambda reader is not reading correctly, at 19.5, I'd expect some hesitation

 

I ended up having a few boost leaks and my AFR went down about a point. The light still flashes when the car isn't under load and using launch control/ rev limiter at 5k. I believe it's just the phantom knock or maybe it's just how the car is at this point. I am getting the car re tuned.