Thread: P0101 MAF...Replaced and still throwing code HELP!

So the new (to me) GTP was throwing a MAF code so the previous owner replaced it. Its still throwing the code (which is why he sold it ot me cheap).
I hooked up my scanner and at idle it was showing the MAF at .60 lb/m is this within range and what else can i do to diagnose why its still throwing the code? After the car warms up it runs fine but when its cold it has a hard time holding idle and dies a couple times.

Give your fuses a check. A 15a ignition fuse comes to mind. Other than that, maybe you just got a bad MAF? Try unplugging the MAF and then starting the car and see if it eventually smooths out. If it does, then turn the car off, plug the MAF back in and restart. If it runs like junk again then you probably have a bad MAF, which is possible for even a "new' one.

Originally Posted by FordMan77

Give your fuses a check. A 15a ignition fuse comes to mind. Other than that, maybe you just got a bad MAF? Try unplugging the MAF and then starting the car and see if it eventually smooths out. If it does, then turn the car off, plug the MAF back in and restart. If it runs like junk again then you probably have a bad MAF, which is possible for even a "new' one.

Thats just it...The car seems to run fine with the code. The only thing I notice is when getting into a heavy load or after about 5psi of boost it sputters. Other than that it idles and drives fine.

Is the MAP HG supposed to fluctuate? I just hooked up my scanner and it is showing a constant 28.1hg, when i drove it around the number only varied slightly and it went up IE 32hg. I thought it was supposed to read vacuum and boost. My boost gauge is working and even just sitting at idle if i give it gas it will go to 0 which i know it should but im not sure about what the live MAP sensor should be reading.

Sounds like you have a mess of problems... Check all the vac lines, and make sure the maf has power going to it (pink wire).

Originally Posted by darkhorizon

Sounds like you have a mess of problems... Check all the vac lines, and make sure the maf has power going to it (pink wire).

I do have a few issues but that's why i got the car so cheap. Its snowing out right now but if the MAF didnt have power going to a wire wouldnt i NOT get a reading from it with my scanner? I know that while sitting still if i give the car gas the MAP reading doesn't change, should it?

I would think it should change. As RPMs increase vac decreases, unless these motors are different.

Thanks for all of the help guys!! I cound a vacuum leak under the snout where the previous owner hooked up the boost gauge. Now my MAP is working correctly, the fuel trims are down to about +/- 2-3. I took it for a ride and under boost its sputtering so i came home and pulled a couple plugs and found they are worn out. one of them was gaped at .80 and the other at .85. The gap looks huge, I run a .32 on my supercharged mustang but i run 16lbs of boost on that car. What should the gap be when i replace the plugs and wires?

Thanks again!!!

Ahh, the vac T under the snout. That likes to leak even stock. I'd gap them at stock (.055) IIRC and call it a day. Holy cow, .080??? No wonder it ran like junk. Heck, my GT started running rough when my gap was at .065, lol... Here is a cut from the safely modding your 3800 thread that discusses plugs


4) Spark Plugs - Change out those stock spark plugs with new ones to restore any lost power. Brands that most tend to go with are either Copper Core Autolites or NGK Spark Plugs. Get these at your local auto parts store also. They range as follows in order from hottest to coldest plugs...remember...you want the hottest spark possible...so running a super cold plug on a larger pulley to combat knock isn't the best plan...ACD's, AL606's, and AL605's are basically for stock cars or very small bolt ons still running the stock S/C Pulley or modded N/A guys...you want to keep a hot spark. NGKTR55/AL104's for your 3.4" Setup, TR6's are a tad cooler...best used around the 3.25" pulley area, and AL103's...are for the extreme supercharged application...3.0" pulley or lower. Here is a picture to reference the firing order and the correct coil number if yours aren't numbered or you just need a quick reference picture: http://i33.photobucket.com/albums/d6.../plugwires.jpg

AC Delco Factory Replacements: Stock
Autolite 606: Stock
Autolite 605: 1 Heat Range Cooler
NGK TR55: 1 Heat Range Cooler
Autolite 104: 2 Heat Ranges Cooler
NGK TR6: 2 Heat Ranges Cooler
Autolite 103: 3 Heat Rangles Cooler

Originally Posted by FordMan77

Ahh, the vac T under the snout. That likes to leak even stock. I'd gap them at stock (.055) IIRC and call it a day. Holy cow, .080??? No wonder it ran like junk. Heck, my GT started running rough when my gap was at .065, lol... BTW, check out the "safely modding your 3800" thread for proper plug type/brand and gap. That is what you should run in it.

Thanks, I will check out that thread. I know the car has an intake/u bend delete/3.4 pulley and a tune. Yeah you should see this gap, its literally the thickness of a house key lol

In that case the TR55's or AL 104's look like what you should be running in it.