alextz

So I recently found I had a small exhaust leak due to clamps on my header to Y pipe slip fit had slipped. Fixed that.

Then I found that my throttle body bolts were a little loose where it bolts to the intake manifold and potentially my intake manifold bolts were a little loose (got about 1/2 turn to tighten to 90 inch/lbs). Assuming there was some type of vacuum leak...

now the car runs very rich. STFT at idle or in park reving to 1500 RPM shows -10 STFT.....

Car was tuned previously (when the car could have had the intake/exhaust leaks), does that make sense that the car is running rich now that the leaks are fixed??

Thanks!

chaase

Your fuel trims will be off because of the exhaust/intake leaks. This can cause extra fuel to be added. The computer should adjust itself after a few miles. You can even try doing the idle relearn to see if that cleans it up faster.

alextz

I dont have LTFT enabled, so there is no learning over time, just instantaneous STFT corrections

superjet701k

I have same issue, I'm stumped

onspeed

Car needs a retune if it was tuned with an exhaust leak. Whether it was tuned by fuel trim data or a separate wideband o2, your tune will be off now.