2002 Sport Trac Masairflow ?

[Kona33]

My ST 4.0 started running bad, missing, rough idle. While trouble shooting the problem I removed the intake hose, and masairflow sensor then started the vehicle. it ran great. Put it all back together, and it started missing again, disconnected the mas and it started running fine. I replaced the mas, no change.
Anyone have an idea of what's going on?

 

[fritz24]

When you replaced the maf did you reset the pcm and enable it to relearn the idle? Check the harness for possible crack on wires. How about tune up? Do have any dtc's?

 

[Kona33]

Not sure how to reset the pcm. Lots of codes, multiple cylinder misfire, fuel codes, sensor codes, several pages. A tune up is due, but it runs fine without the mas plugged in. Most of the motors I've messed with wont even run with the mas out of the loop. The lazy in me says just run it like that, but I know it could cause other problems down the line.

 

[Kona33]

Just watched a video on resting the pcm. In proses now.