Expert: Skip Bollinger - 11/5/2006

Question
Hi i have a 2004 ford mustang GT. I got and engine service light. took it to ford. i got two codes. P0102 - which is the MAF (mass air flow meter) they tested it and they said its good. Also i got a P0174 code, which is i am running lean bank 2. first of all what and where is bank 2 and 2nd what can i do to fix this problem. I have a few modifications to the car and i have an A/F ratio gauge in the car as is and it even shows a bit of a lean condition. The tech at ford said i need to up my injectors from stock, but im still hesitant to do that. i have had all of the modifications on my car for over three months before this condition started. The car backfired for a little while after HARD acceleration. I assumed that was possibly a clogged fuel filter. still not sure. I had a mild exhaust leak that i have since fixed, but the car still runs lean and pops every now and then. On a cold start the car idles really high and takes probably ten to fifteen minutes to calm to a normal idle, if it even does come back to normal. Any thing you can throw my way would be awesome! Thanks, CJ

Answer
CJ,
  I'm a Parts Specialist NOT a Tech but I sell High Performance add on's.
  Stop right here. You have modified the engine so ANY stock specifications have gone right out the window. You need to contact the manufacturer of the NON STOCK components to get their suggestions. I will continue, however...
  When Ford tested the MAF, it may be good but not good for the setup you now have. It's like testing a Holley Carb that flows 500 cfm. It may test good but will NOT work on a 700 cubic inch engine... Make sense??
  Bank 2, I think (as I said, I'm not a Tech) is the bank opposite of number 1 cylinder.
  The backfiring you describe are "traditional" lean conditions caused by various problems. What I would do is take the car to the dragstrip. Make a HARD pass and shut if off immediately. If it backfires or whatever, keep your foot in it. You don't want the plugs to see any deceleration or idling. On the return road, pull the plugs and read them. They should be a light brown. If they are white or show blistering, the engine is running lean or the plug is too hot. Again, contact the manufacturer of the modifications you have added. You never did tell me what modifications you made.
  In closing, ya I'm about done, if the car backfires, it can cause vacuum hoses to blow off or just burst. I'd inspect those very closely too.
  CJ, Good Luck. I hope this helped. Again I'm just a dumb ass Parts Guy, NOT a Tech.
  Skip