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Discussion Starter #1 (Edited)
Driving me CRAZY --> "P0102 - Mass Air Flow (MAF) Sensor Circuit Low Frequency"

So.. problem lies within the topic title. I've read countless forum threads about this code, yet, code still keeps coming back.

Car: 2002 Grand Prix GTP ~137,000 miles on it, only mod FWI.

Issue:
-P0102 is the ONLY code that shows up, everytime.
-Car runs fine with MAF unplugged, idle will bounce between 500-850 sometimes
-Car runs fine with MAF plugged in under normal driving, hard acceleration sometimes causes the rpms to increase, stick for a moment, increase, stick for a moment etc.. it will do that under hard acceleration 2-3 times up to 5-6 times.

Things I've done:
-Replaced PCV Valve
-Cleaned MAF, three times
-Tried a MAF that is in working condition
-Briefly checked over VAC lines, visual inspection for cracks
-Cleaned MAF connectors, checked wires for problems
-Cleaned throttle body
-Checked the MAF screen for debree
-Checked over FWI for problems, none (filter is only about 7k miles old, hasn't needed a cleaning or oil yet)



I have a hunch that the LIM gasket is going to need a replacement that I'll do on next oil change, though I doubt that would cause this code. It is driving me crazy, sometimes afraid to pull out in traffic due to the high RPM "choke" I don't want the car to die or choke enough I can't accelerate decent to keep up. PLEASE any ideas would help a lot!

-Edit
Some things I've read around on other threads that would cause this..
Overfilled oil / dipstick not seated properly -checked
Pull top O2 sensor on downpipe, reset code and floor car -UNchecked
EGR Flange leak -UNchecked
Clogged Injectors -Unchecked

Anything I haven't checked yet weren't a high priority on todays list due to being unsure how this pop a MAF code.
 

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is the car running rich. Because i had do some mods and my tune got to where it was running rich and it keep setting the same code.

another thing was i had an O2 that got burn up on the rear exhaust pipe and it set the maf because it was running to rich. you would happen to be able to scan it anyway could you.
 

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Discussion Starter #3
I do not have a scanner. I've been driving up to the local parts store to use there scanner to get the code. What type of scanner would I need to check it?
 

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it really all depends on how much you want to spend. i know alot of people around here have aeroforce gauge scanners. my self i have hptuners. but there are also hand scanners. but hptuners is like $500 aeroforce is like $240. there are others. i'm sure someone else can chime in on this one.
 

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Discussion Starter #5
If worse comes to worse I could just suck it up and drive it like a grandma until I get the money or find someone to just scan it.. not as fun not being able to hear the whine every now and then though :(.

I'll check out the 02 sensor after the cat tomorrow if weather permits.
 

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The condition you described under hard accel sounds like it's starving for fuel at those times. This can cause a p0102 code. If I were you, I would suck it up and find a good tech with a good diagnostic scanner and scan under these conditions and confirm what you described. Then you can spend your $ correctly.............

Jake L.
 

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Discussion Starter #9
Fuse.. one of the first things I checked, it was fine.

Not having any luck for finding someone that doesn't charge an arm and a leg with a go diagnostic scanner..

Still have the "choke" problem coming up.. starting to appear at lighter and lighter throttle.. still random, not a constant thing every stop. I've found 2 new suggestions, MAP sensor, and the fuel pump resistor.

Either of those seem like they would cause this? I'd hunch the resistor over the other.. may try the bypass method I saw and take it for a spin.
 

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Did you figure out what it was because I have the same code (0102 & 0171)? I cleaned the MAF but the problem came back. Today I cleaned all the sensors connected to the intake & the K&N air filter. The Idle Air Control was the only one that looked bad, a lot of carbon. Put it all back together but, only had time to drive a short distance, no codes. I'll test drive it again tomorrow. Let me know if you figured it out.
 

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P0102 will set if the maf is unplugged or it is reads zero while plugged in.
 

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If its sputtering while idling you can spray carb cleaner over the vac lines and blower gasket, LIM gaskets and see if the idle changes or settles, if so you have a vac leak
x2, good logic: a vac leak could set this code.
 

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I have had the same problem before

I had the same problem that you are having awhile ago after i had to replace the intake gasket, and the carb cleaner trick fix it, i had a vac leak. the only thing else that i can think of that would do it would be the 02 senors, i would find someone on here that lives close to ya with a scanner and scan the 02 senors if you do not have a vacum leak!
 

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P0102 will set if the maf is unplugged or it is reads zero while plugged in.
Thanks for everyones help.
I tried spraying for a vacuum leak and didn't find one or hear any change. Borrowed my neighbors snap on scanner and when it misfired the MAF(Hz)=0 and stayed there until I tapped the sensor with a wrench then it went to around 2200. So does this mean it's definitely the MAF sensor?
Edit Also the book says the HO2 SNSR-1(mv) should fluctuate constantly from 50mv (lean) to 800mv (rich) mine is jumping from 175 to 750 but mostly staying in the upper range. What should the LTFT & STFT be at idle be because the LT actually went into negative #s when it misfired?
 

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does this mean it's definitely the MAF sensor?
Could also be a wire or the conector. (I thought you already tried a different MAF)

I wouldn't worry about the trims right now, the bad sensor readings will cause some moving around anyway...
 

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Sounds like you have completely conclusive evidence that the MAF is BAD. Question is, why didn't you do this scanner test a week ago? I have seen several do this. Something in the internal circuitry goes open circuit when hot. The next issue is, will you be able to get a good "rebuilt" component. There used to be some good pricing on new GM units but that has gone by the way-side for remans........

Good luck, Jake L.
 

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dac2004 had the original post & problem, he might have tried a different MAF. I just found this thread after doing a search. Since I had the same code I asked if he figured it out on his car. I was just checking with the experts to confirm it couldn't be something else causing the problem besides the MAF sensor because they are not cheap, the dealer wanted $280:eek:.
Later I was tapping lightly on it and the revs were jumping up & down, so it's definitely the sensor, right?
As for the scanner I just found out yesterday that my neighbor had one, he hasn't used it in years.
 

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What brand should I buy? Hitachi & Python are around $150 but Jet & Granatelli claim 45% better flow and 10 HP for around $250, still cheaper than dealer. Any one ever try any of these? AC/Delco is $213 new or $172 remanufactured and A1 -Cardone is $135 but I've never heard of them. I think someone warn in this or another thread about bad remanufactured ones. Any help is greatly appreciated.
EDIT: I found 1 from Ed Morad's store and was wondering if it's safe to drive the car with the MAF unplugged while I wait for delivery? IIRC I thought I read in another post that it was:hmmmm::dontknow:
 

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Unplug and drive until you get the new maf. Not an issue as our cars are expected to revert to the tables for info if a sensor fails.

I would suggest against WOT or hard throttle until you have the sensor and the pcm can see true information.
 

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You know, a better throttle body comes with sensors and more HP... Just a thought... A repair is always a good reason to sneak in an upgrade!
 
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