Did you have the same exact problem before and after replacing the MAF sensor? Or did the MAF code start popping up after you replaced it? I'm just curious because almost every vehicle I see with a MAF out of range code is either caused by the wiring or some other system that is causing an air/fuel mixture problem. The computer can only guess that the MAF sensor is reporting wrong. A lot of the time you'll get lean codes when a MAF sensor gets dirty, for instance.

 

I had the wiring redone as well. I used the 100800g maf that is the same model listed on Atlantic british website as original equipment.

 

Good, that is the correct MAF, now so we can help you, what is the fault code number you rate showing, there are 5 of them and each has a different meaning.

 

I will check later today.

 

I took it to a different mechanic today who thinks it may be the crankshaft position sensor causing all the problems. Will a bad crank shaft sensor make it run rich?

 

Now you have found a fool who know little or nothing about a CPS which doesn't even close to your issues. Again, what is your MAF fault code number??????????????

 

CPS? Did you mention to him that you just replaced that? Do you know HOW he tested it?

The only thing that I've ever heard about a GOOD CPS causing problems on these trucks is when they have the wrong shims in them. I've heard that it can cause it to go into limp home mode.

Myself, I won't replace a single part until I know for sure what's bad. Repairs are much cheaper and much more effective that way.

 

Things that can make an engine run rich are things like the MAF sensor, MAP sensor, injectors, PCM sending or receiving wrong info., shorted control side wires on the fuel injectors, etc.
The o2 sensors can cause problems like this if they get stuck lean, but they just trim the fuel and in a lot of cars the PCM will ignore it and start using substituted fuel trim values if the reading appears to be too far out of spec compared to readings from the MAF, MAP, etc.
The only way to pinpoint the problem is to test the sensors manually, or with a scan tool that shows live data. However, if the PCM is using substituted values, the scan data is useless. So basically, if everything looks completely normal on the scan tool, you may have to test them manually.
That is why I don't change any parts until I'm SURE what's wrong.