I have a 2000 dakota 4x4 qc with a 4.7.I have been having a few engine codes keep coming on for the past 2K miles. I havechanged O2 sensors and Head Gaskets and Camchaft Sensor and a fuel injector, but it still throws a code P0171, lean on left bank and P0207, circuit malfunct on injector 7. I need help!!!!

 

As for the lean on left bank.. Most problems would almost defintely have been on both banks. So i'd say that you have either an intake leak on the left bank, or a bad pre-cat O2 sensor. I know you just said you changed the O2 sensors, which was a good place to start, but do check to make sure that you've not inadvertantly created an intake leak at or after the MAF.

 

its telling you that you basically have a clogged injector #7...

 

before i changed the head gasket i had cleaned the injectors with proclean in the fuel rail. they looked real clean when i pulled the heads off.
i used break lean around all the gaskets to see if there was an intake vac leak, but was unable to find anything. is there a better way of checking for vac leak?
is the maf the mass air flow sensor? if so where is that located?

 

i had just changed the the upstream O2 sensor this past monday and everything was great for about 200 miles. i stepped into the gas a bit and the light for lean condition came back on. the O2 sensor is a bosch. i did notice a trace of oil or some sort of liquid on the harness connection. could it have shorted it out?????

 

Ok here is the scoop. P0171 Is most likely NOT A 02 relasted issue in most cases. The Code is generated by lack of vacume at the Intake, witch causes less vacume at the manifolds thus causing the engine to think its not getting enough Fuel. The cause could be a Multiple of thing.. Ie, Intake, Throttle Body, Plinuim Gasket/Plate, Booster, Booster Hoses, PCV Valve, Breather Hose, Gaskets, Cracks.

 

this was a 2 year old post.......