check engine light

nate12281

New Member
Jul 27, 2006
10
0
0
1995 mustang gt my check engine light doesnt come on untill i hit the gas i give it gas real slow it will drop rpm almost enough to kill the car but quickly jump back up the car does this while in neutral and when taking off while im driving down the road shifting threw gears i have no problem only at take off and in neutral and suggestions ?

i dont have a code reader so i went to advanced auto and they did the KOEO test for me it came up passed but i had code 157 and code 158 in my memory but the code reader didnt know the definitions of those stored in my memory

i did the KOER test myself with the jumper wire but i was reading it will flash 4times being its a v8 it does that then it will idle back down and flash once then im suppose to gun it but my problem is it dont flash just the once it flashes 3 times after the idle comes back down so im confused about that part of the test
 
Those codes are pretty intriguing. 157 is MAF sensor signal voltage too low and 158 is MAF signal voltage too high. I don't know how it could be both, so I'd guess you need a new MAF.
 
I agree that that's a little funkalicious.

I'd clean the MAF wires, reset the KAM (disconnect the battery, turn on headlights for 10 seconds, turn off headlights, and reconnect battery) and take a test drive.

Good luck.
 
nate12281 said:
yeah i will try and clean the maf wires but they look so tiny like they would break so easy im guessing carb cleaner and cue tips ? ill keep you guys posted
This article might be helpful. That said, I really really dont like to hit the wires with a Q-tip or a hard stream of Electrical contact spray.

Good luck.
 
well i cleaned the MAF wires today got them looking new they used to be black i turned the key over started the car and check engine light came back on and its still doing the same thing i might end up just buying a hole new MAF i probally need to run the KOER test first id think ?
 
yep sure did i took the negative off the battery for 10 mins and did the lights like you said then turned the key over it doesnt come on rite away the check engine light but if i sit there and give it gas let it idle back down do that a few times it will start to loose power and drop in rpms then the check engine light comes on then the next time i goto give it gas it will drop in rpms and quickly jump back up then it will idle back down and jump up and down in rpms i did the KOER test i got 4 being its a v8 then i got a pulse then i got 159 159 so the maf is or was out of range im for sure going to get a hole new MAF now ill keep you guys posted