Dzmaro

I have a 97 z28 m6 and I installed pacesetter smog legal headers and now car has ses light with p100 code checked the volts on the pink wire and there at 11.7 checked all grounds and for any burned or cracked wires and I cant find nothing got a new MAF sensor and still same thing im lost. Aldo the eng sensor was blown put new 1 in but ses light still came back on.

Dzmaro

Also car runs fine no misfire or sputtering nothing

Injuneer

When the MAF sensor circuit fails, the PCM will ignore it, and default to calculating the mass air flow using the speed-density method. You may not notice any difference.

When you checked for 12V on the pink wire, did you reference it to the black/white ground wire in the connector? Connector off the sensor?

The code sets when them PCM checks the frequency signal from the sensor, on the yellow wire, and does not see a significant change in frequency for 4 consecutive readings. Does your multi-meter have a frequency scale? If so, check the frequency reading on the yellow wire to see if it changes when you move the throttle blades.

Dzmaro

I checked for 12v on the b/w wire and it was 11.7

GaryDoug

Sounds like you broke the ground wire to the block just above the starter. The black/white wire should read zero volts. It goes through a splice to that terminal mentioned above.

Dzmaro

Checked the ground by starter already its all there and good

GaryDoug

You are not listening. If you have anything but zero volts at the black/white wire at the MAF sensor, there is an OPEN CIRCUIT from there to the ground in the diagram. Find it.

Dzmaro

When i checked for 12v at the pink wire i grounded it to the b/w wire and got 12v not getting 12v from just the b/w wire

Injuneer

Unfortunately, post #4 did seem to indicate you measured the voltage on the black/white wire. That's where the confusion came from.

The main issue would seem to be no frequency signal from the MAF sensor. Since you have a known good sensor, it would appear the main possibility is damaged pins (any one of them) in the connector, or a fault in the yellow wire.

It's also possible you have an intermittent break in the pink wire. That is not an unusual problem with the 97's.

Dzmaro

Could a bad 02 sensor set off the code?

Injuneer

No. As already explained, P0100 sets when the MAF sensor frequency is not changing like it's supposed to.... it has gone static. There is no way an O2 sensor could affect the output of the MAF sensor. It's measuring the air going into the engine, and nothing else.

However, an O2 sensor could turn on the SES light.

Did you clear the P0100 code, and rescan after driving to make sure the same code turned on the SES light? The suspicious item is the blown fuse. Why did that blow? When it blew, it would shut down the MAF, and set P0100. But that does not mean the MAF sensor blew the fuse. You have to look at the other things that are on the circuit, :
-O2 sensors (powers heater circuits only)
-Reverse lockout solenoid
-Skip shift solenoid
-Brake switch

If you have defeated the skip-shift system, typically done by inserting a resistor in the end of the harness connector, maybe that modification is shorting out, for example.