Hey guys, i really need some help with my truck, really rough idle, it shakes out of control and misfires. The diagonostics from autozone says its the MAF sorry dont have any codes.I bought a used mass air flow sensor for my 1999 F150 4.2L V6, but got the wrong one, ended up with one for a 99' 4.6L V8 model. Can not return! Can a 4.2L V6 mass air flow sensor be replaced by one belonging to a 4.6L V8?

 

It's not the MAF sensor!

You likely have the common vacuum leak in the PVC valve elbows.

 

Could the vacuum leak be responsible for the rough idle, constant shaking and high gas consumption? Thanks alot for your reply, really appreciate the help

 

MAF:
The sensor measures a small percentage of the airflow through a sample passage.
It is calibrated for the engine size and fuel injector size the PCM has in it's program.
A 4.6 may run the motor but is not the correct calibration.
.
MAF is not the source of misfires.
Misfires are a lack of uniform cylinder combustion pressures.
MAF only measures the amount of airflow.
Diagnose correctly for the fault.
A the present time you have no stated info to that effect.
Good luck.

 

Yes. Otherwise, I would not have said to check that and would have just let you waste your time and money screwing around with MAF sensors.

 

Although it may not help your mechanical issue, looking on RockAuto's site, depending on brand name and part number, it looks like some MAF sensor versions may fit 4.2 and 4.6 engines. Check the brand name and part number of the unit you bought with Autozone or other retailers that may sell the same product if you haven't already. The numbers will have to match.