I recently purchased a 96 f150. Truck has a 351w w/71k miles on it. The 'check engine' light was on when i bought so my dealer pulled the codes. He said the o2 sensors were bad. He replaced them. The light came back. He brought it to the mech he does business with. They did the same thing. Twice. Lazy *******s. I didn't make it out of the parking lot and the light came back. Again.By this time I was pretty pissed.
So I told them just to forget it. I don't have time to f*** around anymore. I brought it to my local ford garage and told them to pull the exact codes and give me a list. I had done some reading on this site and i had my own ideas.
Here is said list: PO135 02 11 Heater Circuit
P O141 02 12 Heater Circuit
PO155 02 21 Heater circuit
PO171 Lean Bank 1
PO174 Lean Bank 2
They also stated they performed pinpoint test "H30 thru B7". I'm not a tech but I assume that's a more detailed reading?
I have been reading on here that pcm's don't usually go bad and to check the more basic culprits first.(grounds, etc.) I wholeheartedly agree with that assesment. I asked the mechanics about this and they told me it IS rare that pcm's fail. However, they tend to see this problem on trucks in my general year range that have low miles(as mine does. generally speaking my truck "should"have roughly 150K in my best estimate) and that may have been sitting for a lenght of time. This particular truck came out of southern Illinois(or so i'm told. I live in the U.P.) so I don't know it's history.
Soooo..,tomorrow i am going to order the pcm and put the damn thing in myself. But would'nt you know it, it takes SEVEN F***ing days to get it!
So for now i am stuck with the light glaring at me. It's driving me nuts.
I hope this helps for anyone with the same prob. I will post again when it's fixed. Also, ANY feedback from those in the know is always appreciated. Thanks guys.