Hello All. I'm super concerned about an issue I encountered. I just got tuned yesterday by Sean Ivey and put down 362 whp and 336 wtq with all the bolt-ons you see in my signature. Last night, I hit some boost in 2nd gear and the car had a hiccup. The car was then running super rich and shot flames everywhere out the exhaust. The car's service engine soon light came on as soon as the hiccup happened (misfire). The car went into limp mode regulating boost. I swapped all the plugs today for HKS M40XL. Before I installed the plugs, I only had an error code of P0302 (cylinder 2 misfire). I erased the codes, installed the plugs and as soon as I turned on the car, the SES light came back on. Codes were P0302, P0137, P0131. Can any tuning guru help me out? I'm a bit concerned.


DTC P0137: Heated Oxygen Sensor Circuit Low Voltage [SEMSOR
DTC P0131: Heated Oxygen Sensor Circuit Low Voltage [SEMSOR
DTC P0302: Cylinder 2 Misfire Detected

Thanks,
AJ

 

Another note: The car is reading lean on the Wideband when just cruising around without boost.

 

It sounds to me like your oxygen sensor went bad. The front one.

 

I was thinking the same thing. I did a compression test and all cylinders are consistent. When you say front oxygen sensor, do you mean pre-cat?

 

it ended up being a bad maf.

 

If you experience problems the day after a tune, go back to the tuner!

 

Ya was going to say the MAF after reading OP. recently dealt with this with the brother in laws STI. Ran like it was on only 3 cylinders, gave misfire codes and bad o2 / low circuit (lean).
Swapped out MAF with a known working one... boom ran butter smooth.