I just installed a ram air system on my car which has the MAF sitting right over the water pump. I put my new pcmforless PCM in at the same time while I had the hood up. I drove around fine for about 40 miles when all of a sudden it felt like the car hit the brakes. I didn't think anything of it until it happened again a few minutes later. I cycled through the scanmaster readings and saw it was running richer than it had been right after the PCM finished its "learning mode". It also showed a DTC 48 - MAF circuit fault. I tried some hard accelerations and kept getting misses.

After 10 miles of granny driving I cycled through the scanmaster readings again and through my glances caught these:

MAF - 467
LBL - 144
RBL - 137
SP - 44

Yes, the MAF was reading 467 when it should be around 15 - 20 for a light cruise. It was running lean as you can see.

When I got back to my place, I let it idle and checked again. The readings were the same and the car kept approaching the brink of dying. It almost sounded like I had the biggest cam in the world. I checked the MAF right away and saw that the corner was touching the coolant hose on the water pump. I rotated the MAF as much as I could but I don't have the wire extension so it's maybe 1/2" - 1" off the hose now.

This was 3 hours ago, I just started it again and it ran fine but still showed the dtc 48 so I unplugged the battery and will check if it shows back up in about 20 minutes.

Did I fry my MAF? What do you guys think?

 

Car works fine now. Moral of the story: don't let your water pump boil your MAF.

 

Well, I did a WOT run and it happened again, miss with a DTC 48. I really don't want to replace the MAF.

 

Drove around with scanmaster on MAF and the misses I feel while driving are the MAF cutting on and off. It will go between 20 (or whatever, depends on the throttle) and 461, not 467. After some searching I found that this means it's in speed density mode and there is basically a severed connection between the maf and pcm.

I tested the pcm wire for the maf which should read 12v and got 11.8v, close enough so the wire is good. I'm gonna swap my old PCM back in and see what that does.

 

Took a look at the MAF and this is what I saw. The ram air is a tight fit, but I didn't know the air box was shoved up against the screen. Could this be enough to screw up the MAF? The sensors look OK.

 

Don't see the screen issue causing what you encountered.

 

Well, it's been a looong ***** fudgin' day trying to fix this thing. I drove around in speed density for a while and it ran like a dream. LBL and RBL were hovering around 128 the whole time, I almost chucked the MAF. Got some MAF cleaner and a q-tip and gave her a bath. Seems to be running fine now, if a little on the rich side. We'll see.