P2637 - 2004 VW Jetta

Question

I have a 2004 VW jetta 1.8 turbo with the auto tiptronic Trans

The car started idling rough and my check engine light came on, I read the code, and it displayed misfire 301,302,303,304, and 2637. I checked for vacuum leaks and found and fixed a small one. Now the car ASR light came on while the car is parked in the garage idling; now I read the code and I get code 2637 Mass Flow Controller and 120

I turn the car off and removed the MFC and cleaned it and put it back in and started the car, the light again came on. I took the car for a drive and now it slams in to gear when it shifts there is a reduce power.

I replaced the MFC with a brand new one hoping it would fix the problem, but it did not???? The light still stays on with the check engine light code reads 2637 and 120

If I turn the car on and rev up the motor and keep it there ther lights will not come on

Answer 1

P2637, MAF (mass air flow) feedback signal

You need to look for false air, this includes the MAf air duct, Just to let you know the MAF in the VW ihas a high failure rate. The fuse need to be inspected There is none for the MAF, but you have some for fuel pump. Inside the engine fuse junction box.If you replace the MAF with a new one,and you are absolutely sure of no vacuum leak causing false or leak,The fuel presssure maybe low ,if low does and can set of MAF code P2637,