2002 Dodge Caravan P0171 SYSTEM TOO LEAN Bank 1

2002 DODGE CARAVAN
45,375 MILES • 6 CYL • FWD • AUTOMATIC
Avatar
CSMADHATTER
  • MEMBER
  • 6 POSTS
My check engine light came on and i scanned the code. It shows a P0171 (system too lean bank 1) and i did some research. Most online resources list MAF sensor, vaccum leak, low fuel pressure, or O2 sensor as the problem. This vehicle is not equipt with a MAF sensor, instead it uses readings from the MAP sensor. I could not locate any vaccum leaks (i sprayed starting fluid around vaccum lines and mating surfaces between the head, intake, etc. I also replaced the fuel filter, which was original. I then reset the light and drove the car 21 miles before it came back on. When i checked it with the scan tool, the code P0171 was stored again, but the only rediness monitors that had been run were Fuel System, Comprehensive Component, and Misfire. All others were still set to "Not Ready". The best i can come up with is either the fuel pump/regulator (it is all one assembly) or an O2 sensor, or a MAP sensor. Anything will help, please and thankyou!
Dec 15, 2008 at 10:53 AM
Advertisement
Avatar
ZACKMAN
  • CERTIFIED EXPERT
  • 4,202 POSTS
Save your money from buying the fuel pump or O2 sensor. Test your MAP sensor. If the voltage too low (high vacuum), it will throw the PCM thinking that you are at idle, and cuts fuel to the minimum, thus setting lean condition.
Dec 15, 2008 at 6:53 PM
Avatar
CSMADHATTER
  • MEMBER
  • 6 POSTS
I have replaced the fuel filter, the O2 sensor and the MAP sensor. I am still getting a P0171 (system too lean Bank 1) code. I also cleaned the throttle body and tested the fuel pressure, it is 62psi at the rail (where i spliced the line) The stock specifications show 58psi, I also noticed with the engine running, if i gave it throttle the fuel pressure would drop to 60psi... Does this mean anything? All help is appreciated, thanks a bunch.
Dec 16, 2008 at 9:45 AM
Advertisement