Guys, here's a wierd one I could use some help with.
My truck is completely home-made using parts from many different wrecked trucks, it's a mixture of 1999 and 2000 parts.
I even had to get a new V.I.N. issued for it.
The body and frame are 2000 F150 supercab 4x4.
The 4.6L engine and wiring and PCM is from a 1999.
My SES light is on and I have been told the problem is in the oxygen sensor circuit but all the sesors are funtioning correctly.
I assume that they are sensing a incorrect air-fuel ratio??
I've been doing some reading on this site and read about guys modifying their MAF by removing a post to allow for more air flow and inadvertantly caused a lean condition.
The MAF on my truck has no post, it is just a small stub sticking up into the air intake.
Is it possible that I am using the wrong MAF for the 1999 PCM and causing an incorrect air-fuel ratio??
Could this MAF be out of a 2000 truck or a 5.4L truck??
The engine also pings under load.

Any ideas??

Thanks
Dave