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P0171 with new MAF sensor

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dman623

New member
Hello. A few days ago my 2000 3.8L Grand Prix stalled out and wouldn't run. My error codes were for the MAF sensor. I've had problems with it before and this time cleaning it didn't seem to work so I replaced the MAF sensor which got the engine running but not well. I was also having problems with idle so I replaced the IAC. This also improved the situation. After these fixes I got a code for the MAP sensor which upon taking it out was in bad shape and cleaning it didn't make a difference so I replaced it as well. Now where it gets interesting is that I was "borrowing" a remanufactured MAF sensor (and the engine was running well with no codes) and when the brand new sensor arrived I switched them out (they were the same price but the new one had a lifetime warranty, I'm regretting this). After switching them out I'm getting the infamous P0171 code.

I have read around on this forum including posts by "BillBoost37" and have tried a few things out. I cleaned the new MAF sensor. I have examined all my vacuum tubes and have examined my PCV. My PCV still rattles and appears to be functioning correctly. I had one vacuum hose that was a little loose that I pushed back on. I didn't do too much with my EGR because I'm honestly not too sure what I'm looking for there.

Guy at the auto parts store said it may be my O2 sensor. I did get a code with my O2 sensor about a year ago but it was with a MAF code and after cleaning the MAF sensor I didn't get that code again.

Suggestions on where to go from here? Thanks for reading.
 


I like the way you think already. :th_winking: On the P0171 smack the parts store dufus for suggesting the O2.

How do the wires going to the maf look?
What brand is the new maf?

Our engines seem to be pretty picky about certain parts, maf can be one.
 
BillBoost37 said:
I like the way you think already. :th_winking: On the P0171 smack the parts store dufus for suggesting the O2.

How do the wires going to the maf look?
What brand is the new maf?

Our engines seem to be pretty picky about certain parts, maf can be one.
Click to expand...

The new one is a Duralast from Autozone. Not sure about the remanufactured one. The wires going to the MAF seem fine. I haven't removed the plastic sheathing to take a close look. The parts I can see there doesn't appear to be any breaks in the insulation. I've cleaned the connector a few times with MAF sensor cleaner. The remanufactured one had some electro-grease (can't remember the proper term for it) on the connector that I decided to wipe and clean off. The new one didn't.

The other thing I noticed is that my original MAF didn't have any leads on the side. You have the standard T-shape with the hot wire inside. The remanufactured one had a side area for these leads but no actual wires. The new one has actual leads on the side. Not sure if that makes a difference.
 
I'm a little confused by the leads on the side, can you post a picture to show us what you mean.

On the duralast, might be the issue.
On the wiring, because it's directly over the exhaust, that can sometimes cause the wires to break down. If they look good, assume they are good.

I'd be inclined to think the maf is not making the pcm happy.
 
BillBoost37 said:
I'm a little confused by the leads on the side, can you post a picture to show us what you mean.

On the duralast, might be the issue.
On the wiring, because it's directly over the exhaust, that can sometimes cause the wires to break down. If they look good, assume they are good.

I'd be inclined to think the maf is not making the pcm happy.
Click to expand...

AFH50M05MAF10-2T.jpg

The red circled area is what I'm referring to. The original didn't have the part on the side. The remanufactured had it but it was empty. The new one has leads inside of that area.

Hmm I think I'll try to get back the remanufactured MAF.
 


BillBoost37 said:
I've never seen that area on a maf. Don't know what to say.
Click to expand...

I've been getting a lot of that today. Well I'm in the process of getting the old one back but everyone at that store is having a heart attack about how to take care of it. The scary part is he told me on the phone that they don't sell Duralast MAF's. I had to convince him that is was indeed duralast.
 
Hi

I also have the Duralast MAF which I purchased last year and since then I get the 0171 code. Before getting the new MAF from Autozone I never had any codes on my car. Now since I purchase the Duralast MAF I get the 0171. To this day the engine runs great and also gets great mileage so I am living with the Duralast MAF for now. I am going back to Autozone soon to have this resolved! I did talk to them a while ago and they say they will exchange with a new one anytime without any issue. About 6 years ago I went throught the same problem and it took 4 new MAF to finally get no codes. I believe the best one to get is an original GM one!
 


71gs3504sp said:
Hi

I also have the Duralast MAF which I purchased last year and since then I get the 0171 code. Before getting the new MAF from Autozone I never had any codes on my car. Now since I purchase the Duralast MAF I get the 0171. To this day the engine runs great and also gets great mileage so I am living with the Duralast MAF for now. I am going back to Autozone soon to have this resolved! I did talk to them a while ago and they say they will exchange with a new one anytime without any issue. About 6 years ago I went throught the same problem and it took 4 new MAF to finally get no codes. I believe the best one to get is an original GM one!
Click to expand...

Sounds like Duralast is a problem then. I'm having them give me the remanufactured one today finally. I think the remanufactured ones are originals so that probably makes the difference. I'm going to need to learn to love junkyards I think. I've never used them before.
 
Imagine a place where you can get parts in the same color as your car.. slightly faded like your car and a couple of scuffs...just like your car. Put on a fender and likely no one ever knows. And..they are often pretty cheap. Say a maf goes for $20 .. you like that price better than the crapmaf price you paid I bet.
 
BillBoost37 said:
Imagine a place where you can get parts in the same color as your car.. slightly faded like your car and a couple of scuffs...just like your car. Put on a fender and likely no one ever knows. And..they are often pretty cheap. Say a maf goes for $20 .. you like that price better than the crapmaf price you paid I bet.
Click to expand...

Bill do you know if the 0171 code is active can an emission inspection be done without any issue?
 
you'll fail inspection if the check engine light is on.

im running a junk yard maf for 2 years now, cost 40 bucks,

check the wires to the maf for damage, bad wires will toss the same code.
 
I believe Scott is right, but I'm not sure of PA laws. The ways you guys screw up roads for 50 mile stretches amazes me.. so who knows what your emission laws could possibly be.
 


Yep. Just put the remanufactured OEM MAF back in and it runs like a dream. Thanks for all the responses and help. While I'm here does anybody know about a common oil leak problem on 2000 grand prix? It's a slow leak maybe a quart a month and I can't figure out where it's coming from.
 
valve covers leak, oil pressure sensor leaks, near the oil filter, oil pans leak as well.

best to de grease the engine and tranny, top to bottom, then after a day re check for fresh oil leaks.
 
Well I'm having problems again. Really strange. I've driven it now for almost a week and it was working great again. Now suddenly it's back to a hard start with inconsistent idling. I'm getting a P0102 error again for MAF circuit A low input and out of the blue I got my P0141 code again for an O2 sensor. Could it be a faulty O2 sensor is sending bad signals? This wouldn't effect the MAF would it?
 
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