canuck94z28

This is some background.I finally got my 94Z running& i,m getting a code 48 on my Lt1 scanmaster.I,ve fixed the yellow wire,it was broken off(i bought a new maf pigtail connector).My first ? is how do you erase the dtc on a scanmaster(i need to determine if problem is fixed).Also when i started car i watched my maf reading on the scanmaster& it was reading @ idle 461 gps(guide says it should be 0-255).Why is it so high,is my maf going bad,etc.Also i noticed that the collar (rubber piece between K&N& mass air housing) has gotten so hard it won,t seal properly.This maybe is giving me these high readings.My last ? is where do you get a new collar;i probably could put this one in some very hot water but that is only a band aid fix.Any opinions would be most appreciated.

Injuneer

You can not clear codes with the ScanMaster. All you need to do to clear them is pull the "PCM BAT" fuse for 30 seconds. In 94 the PCM BAT fuse is in the panel at the end of the dash. In 95 they moved it to the box under the hood.

If you are seeing 461 GPS at idle, the MAF sensor is not working. Generally means there is an open circuit. First check for 12V between the pink wire and the black/white wire in the harness connector. If your multi-meter has a frequency range, hook it between the yellow wire and the black/white wire, and at idel it should be in the range of 2,500Hz. If you have voltage to the MAF sensor, and don't have a signal out of the MAF sensor, most likely the MAF sensor is deceased. Make sure you check the connector pins for damage.

canuck94z28

Thanks Injuneer for that reply.Yesterday i fixed that connection between the K&N tube& mass air meter;the tube was positioned too high!.As i,ve deleted the air pump there is a plug on the tube & it was hung up on part of the radiator.I also cleaned the wires(some of them looked slightly bent) in the maf meter& also removed a screen from maf as well.I,m going there again w/ a voltmeter & measure the volts from those wires& bring along a GM service manual.I will keep you guys updated.

Injuneer

The MAF output signal is not a voltage. Its a variable frequency. You need a multi-meter with a "frequency" scale.

Why did you remove the screen? Not a good idea.

canuck94z28

Ok i pulled that pcm bat. fuse & the chk. eng. light(code 48) immediately came back on after car started.I then took vehicle out for a test drive & vehicle didn,t have any drivability issues.I can purchase a used Maf from a Impala/Caprice/Camaro w/ the LT1(any issues w/fitment?).Btw i had a hunch that i had a dying/dead maf& that is why i removed the screen.Again the car ran great,& the scanmaster showed it,s usual 5.0 kr(it,s done this off/on forever

Injuneer

But apparently you didn't check the voltage at the MAF??? I'd do that before playing parts replacment roulette.