ilikeppie

so i have a 03 f 150 v6 it keeps throwing the code saying both banks are running lean to me this would indicate a bad maf or a vacuum leak i just replaced the maf because of this about 2 or 3 months ago and found a vacuum leak when i replaced the maf this fixed it but the code is back cant find any vacuum leaks and the maf is not that old any ideas why im throwing these codes oh and im only getting 12 mpg highway

goldenyearf-150

had a 99 4.2l did the same thing i ended up replacing the cats in mine i just went back with two instead of the four that came on it they were throwing a code through the o2 sensors which u also have four on at least mine did you should have two on your manifold and two between the two cats on each bank i would get someone with a fairly advanced scanner (not the one you can buy at wal mart or autozone uses) but they can pinpoint what o2 sensor is throwing these code if that is what is causing it i wouldnt just go out and start replacing stuff til i found out for sure i also had an issue with vaccum on mine the grommets that go into the valve cover i think for the egr were deterorated and caused mine to idle rough just a few thing you might look at hope this helps good luck

Good old Bill

Please, talk to the local dealership parts people, and if you can get input from the back counter people, they will tell you about the re-accuring, sales of the intake rubber seals and grommets around the bolts securing the black plastic plenum chamber. You are in Colorado and its getting cold throwing codes, do yourself a favor and call. I'm an 02, 178K, I fixed mine by listening to those who fix this stuff.

08SC

Agreed, seen plenty of those in my time.

- JB

ilikeppie

thanks guys ill check into it i been pretty broke here lately so i cant really do nothin about it :/

jrhoads78

I got the same problem. I may just break down and take it to a shop. Mine also has an AC problem. When I let off the clutch and accelerate it goes from cold to warm air. Not sure why this happens.