MAF confusion

[SHOtgun1]

In regards to my 1995 mtx,
Recently my sho seems to have been castrated. Idle seems normal, however, when I press on the gas in any gear, power seems absent. The engine roars like its trying to move faster but the ******** sound of the tach reaching 4000+ rpms never comes. It's more of a constant growl. Pulled the codes and came up with: 157
I read around on the forum a bit and ran across some advice to unclip the MAFS and see what happens. The car didn't change much at all. Still didn't have any nuts.
My question is whether of not running the vehicle without the MAFS engaged is an absolute guarantee that the MAF isn't shot. That is to say, should I still be looking to replace my MAFS unit even though removing it didn't affect anything? I've cleaned the existing unit, but with 197k on the engine I'm just wondering if it's due for replacement.
Thanks for reading this.

 

[LOUDSHO92]

If you do not have the secondary kick I would first see if they open up.

 

[Toolman]

If unplugging your Maf didn't change anything, I would say that is an
Indicator that your maf is bad, not that it is fine.

 

[AREA 91]

If unplugging your Maf didn't change anything, I would say that is an
Indicator that your maf is bad, not that it is fine.

^^^this^^^

Try cleaning the MAF with MAF cleaner.

 

[Off Road SHO]

My question is whether of not running the vehicle without the MAFS engaged is an absolute guarantee that the MAF isn't shot. That is to say, should I still be looking to replace my MAFS unit even though removing it didn't affect anything?

Wait, let me get this straight, you think you have a bad MAF sensor causing your car to run poorly, so you disconnect it and the car still runs poorly, so you want to know if the MAF sensor is really bad?

If the car runs as if the MAF sensor is missing, the MAF is missing. Without the MAF sensor the computer only commands enough fuel for idling. Sounds like you have a MAF sensor problem. Either the unit is bad, element is very dirty, or the wiring to it is loose or broken somewhere.

Isn't the plug for the MAF sensor the same as another plug on motor?

Tom

 

[SHOtgun1]

First of all, thank you all for your quick, pertinent responses.

'Quote from Off Road SHO': (I suck at forum posting btw ) Wait, let me get this straight, you think you have a bad MAF sensor causing your car to run poorly, so you disconnect it and the car still runs poorly, so you want to know if the MAF sensor is really bad?

In a nutshell, yeah. If my logic is completely flawed then I apologize. My reason for posting was that the information I had previously gathered on the forum all pointed to the removal of the MAFS and how that should have an impact on the drive ability of the vehicle. Since the vehicle did not behave differently at all after the removal, I was simply unsure as to what this meant.

I gave the sensor another cleaning with MAFS cleaner and it didn't seem to change anything. Wiring all looks legit coming to the unit and corrosion appears absent. Looks like it's time to try a new sensor.

Again, thank you gentlemen for your time, it's greatly appreciated.

 

[Off Road SHO]

No, to paraphrase: If you have a bad sparkplug causing a no-spark condition, and you remove that spark plug and it doesn't change the no spark condition, it doesn't mean that that spark plug is good, it means that you still have a no-spark condition, Period. Do you follow what I am trying to say? Now you have to find out why the removal of the MAF DIDN'T change something. It should have.

Do you have a volt ohm meter that you could use to back probe the wires leading into the plug of the MAF sensor? I'm not real sure but I think at idle air flows, the MAF sends 1.0 volt back to the PCM and at WOT air flows it sends back 5.0 volts. But don't quote me on that, I don't have my EVTM manual handy.

Tom

 

[SHOtgun1]

Off Road SHO - :thankyou:
That line of logic makes much more sense than the way I was going about it. In class for another few hours, but when I get out I'll break out the volt ohm and see what I can come up with.

 

[DemonNeno]

Cork your exhaust on both ends. Clogged cats can cause a power issue
Cleaning your MAF isn't always cure. This sounds like a MAF/IAB issue. Invalid measurements
Check plugs by gap and wires by resistance. If resistance can't be measured, a safe (but not entirely accurate) measure is spark color.

A weak fuel pump can be culprit, but you have a MAF code that I would follow up on...

 

[pejohnson]

I just had this same problem, no power at all. I cleaned the MAF sensor and it solved the problem. My engine light would randomly come on and stay on. If I would turn the car off and turn it back on, the light would go off for a while and then come back on. Does your engine light come on? I'm guessing if you cleaned it, and it didn't fix the problem then it's a bad MAF sensor.