I recently had my 93 ranger pop a code 157 which is MAF sensor below minimum voltage. i have done everything I can think of from replacing the MAF and I even went as far as to trace the wires and check for continuity all the way through and everything checked out. My battery is good to go, my charging system is good to go heck even my starter system is good to go even though it has nothing to do with the MAF. I traced the wire from the MAF all the way to its plug in the PCM and checked continuity from plug to plug with good results, I checked all 4 wires. I need to fix this issue. My truck will drive just fine but the moment I let the truck idle it starts to drop off hits 500 RPM and stalls out. i can start it just fine after ever incident of this. My only thought now is that the PCM is going bad. If anyone has ever encountered this problem and got it fixed can you please tell me what you did. I have even reset the codes but it comes back as soon as I start it up. Thank You to all those that help.

 

I'm having the same problem any word on the fix

 

Checked everything besides pcm that's my next step pull it look at it swap my 94 2wd one in mines 4wheel but full manual engagement so should be fine in theory if anyone fixed their issue an update would be extremely appreciated

I checked vacuum leaks and put 2 MAFs in it , checked harness ohm'd out great but should have checked for crossed wires even though harness is in great shape, had an intermittent issue for a few weeks and then I left the MAF unplugged for a week so I could get to work plugged it in and it throws a 157 now. I'm at a loss the pcm would be me throwing parts at it more than likely but being I have it on hand it's worth it.