Mass Air Flow Sensor issues

I just replaced my engine due to a runnaway after Turbo failure. I get a code CEL and although the car runs , but not optimal. It will not boost well, and my fuel milage is about half. So I unplugged the Maf sensor and .... yup she boosts great again, my milage is good as well. From reading here it would appear a new MAF should fix this. I just bought a new one and put it in, and NO difference at all, so I unplugged it again .. and things are good again. I tried the Cage mod by putting Dielctric grease on the plug as well, No change. I'm stumped ... can someone help me?

Hi, Turbo. Are we working on the Passat or Jetta ALH?

IIRC, there have been problems with the MAF sensor wiring. I think you should inspect that. Also, how is the N75 doing and the condition of vacuum lines on the car in general?

Sounds like a MAF wiring harness problem as dieseldorf says. Don't throw out the old MAF.

Hey since you had a runaway turbo, make sure you drain the Intercooler of any oil that may be there.

Thanks for all the excellent advise.... its the ALH Jetta... and yup I swapped out the intercooler and piping with the donor engine. I kept my old MAF and returned the new one. So .. are you suggesting I replace the wiring harness? Who has these? Thanks.

so did you ever find out about the wiring harness?