My car keeps intermittently giving off a SES light. I found out its a p0171- too lean- code being thrown. I thought it was from the tank of gas (Mobil 91) but even with other brands its still comes up. When the light turns on the car feels slower with a flat spot on the throttle at around 3.5k. I also noticed some white smoke and a really rich smell when i turn the car on in the mornings. Any idea what is causing this? My guess is one of the sensors or a leak somewhere.

NOTE: i have one ball, 15% pulley, CAI, plugs, and DT BPV.

 

Check for coolant leaks (thermostat/waterpump/oil cooler/reservoir) I would also run a compression test and check your numbers.

Do you get white smoke while driving? Not steam from a morning start, but smoke. If this is the case, chances are you have a blown head-gasket. Which could also explain the lack of power at certain points of the powerband.

 

no way on the gasket. Ive had a blown gasket on my e36 bmw. there is no oil coolant mixing. The coolant is fine not sure of the thermostat but i dont think that connect with the car running too lean. The compression test sounds fair enough i may have to do that.

As an update. I did notice a small leak in the intake so i installed the stock one back on. The car runs smoother without a rough start up. There is however, the problem with the light and code still being thrown. I'm going to take it to the dealer tomorrow to get a diagnosis.

 

Hey Gar, did you ever find the source of this problem?