2G MAF or MAF Circuit malfunction

[gophishy10]

I live in NY and need to get my 96 GST inspected, but it's throwing a MAF circuit malfunction code. I changed the MAF sensor and it's still showing the code. The car runs fine and doesn't show any signs that the sensor is bad. It's been at my mechanic's shop for about 3 weeks now and he doesn't know where else to go. He's checked the voltage to the sensor and it was good. He's checked all the wires. When I got the car last summer, I had to put a new engine in it. Does having an Apexi BOV have anything to do with this? It was on the car when I purchased it. Any help is appreciated. Thanks!

 

[XiKeiyaZI]

It won't effect the MAF directly, but you're running an atmospherically vented Blow off valve without a way to compensate for the loss of metered air (as if you could anyway). To begin with you should likely recirculate your BOV be either looking into an adapter to allow recirculation or change blow off valves. Also - is it just me or does it look like there is no vacuum line running to the Blow off valve and you simply have a hose looped to the top and bottom nipples? Might want to look into correcting that as well so it operates properly.

Secondly, if you're getting a CEL, try clearing the Code if that hasn't been done. If you continue getting it you may want to have the ECU inspected if the plug/wiring/MAF(s) have been inspected and determined to be good.

 

[gophishy10]

Yeah I've read about that. I wasn't sure if that would cause the check engine light and that code just because it isn't recirculated into the intake like the stock BOV. A vacuum line? Where would that be coming from? And my mechanic did check the ECU and determined it to be functional. We are at a loss except to try converting the entire car back to stock.

 

[gofer]

Did he check for a pushed pin in the connecter itself? Just because continuity checks out with a multimeter doesn't mean that when the plug is pushed on the the MAF that a pin gets pushed and isn't making contact.

 

[XiKeiyaZI]

Yeah I've read about that. I wasn't sure if that would cause the check engine light and that code just because it isn't recirculated into the intake like the stock BOV. A vacuum line? Where would that be coming from? And my mechanic did check the ECU and determined it to be functional. We are at a loss except to try converting the entire car back to stock.

For the BOV, you should have a dedicated vacuum line ran from the intake manifold to the BOV.

Did he check for a pushed pin in the connecter itself? Just because continuity checks out with a multimeter doesn't mean that when the plug is pushed on the the MAF that a pin gets pushed and isn't making contact.

+1 for this information.

 

[gophishy10]

There is a vacuum line running from the intake manifold to the BOV (right side of BOV). As for a pushed pin, I'm assuming he would have checked for that. He's a good mechanic. I'm picking up the car tomorrow so that will be the first thing I check.

 

[gofer]

I'm assuming he would have checked for that.

Assuming things that mechanics do costs you...

$100 x amount of hours you assumed = A broke DSMer with a car that still doesn't run​

 

[gophishy10]

Haha very true. I'll check tomorrow and cross my fingers that it's something as simple as that.

 

[gophishy10]

So it was not a pushed pin. Any other ideas?

 

[gophishy10]

I just noticed today that my apexi air flow monitor is showing zero air flow. Any idea what is causing this?

 

[gofer]

Yes. It means that there's no signal from the MAF to the SAFC.

 

[gophishy10]

What could a cause of the safc not getting a signal? I know for sure the sensor is good.
Another question: I was going through all the vacuum lines and air tubes from and around the intake. I noticed one wasn't hooked up. I followed it back underneath the battery. I removed the battery to get access to the charcoal canister where I noticed that there were two places where a hose was missing. This hose that was disconnected fit on the side of the canister (and runs to the intake). Then there are two nipples on the top of the canister. The one closest to the firewall had a line on it. Is the other one supposed to have a line?

 

[Arthris]

Check the wire going from the SAFC to where it splices into the MAF signal

 

[gophishy10]

Turned out to be the ECU.