Having some MAF issues

**wssix** · 04-24-2011, 11:38 AM

Hey guys,

I have a 2001 Trans Am Ws6, I bought it with all engine mods done by the previous owner (cam, headers and ls6 intake as you will hear momentarily). The only modification I have done is 3.73 gears with a tors. diff posi.

The car has been running pretty rough since Ive purchased it, running very rich and surging at idle constantly when driving it. Attempts to tune have been very hard to try and resolve these issues.

Ive decided to replace the MAF, and ordered a stock MAF (AC Delco 213-3457) for it, in the mail on the way to the house right now

Heres why....

I went out and looked at the setup, it has an slp lid, but the maf has a piggy back connector on it. I noticed that is a Delphi 25168491 MAF which looks like 4" (with no screen)!I researched the size MAF I ordered and it appears that it is going to be 75mm. Now I realized that the stock MAF i purchased is probably not going to work.

Am I wrong? is there a posssibility that this MAF will work if I get reducers to adapt to the size?

I know this sounds very stupid to all those who read this, Im not very knowledgeable with all the setups with these cars and have not been able to find much help the last few hours searching this site/google.

Thanks in advance!

**pajeff02** · 04-24-2011, 11:51 AM

GM updated the MAF from when the car was originally built. The stock style MAF had an aluminum body, a blade and screen -- all of which should be left intact. Stock size was 78 mm if I recall and the replacement MAF is an 85 mm unit. The replacement MAF comes with an adapter harness as it has an integrated IAT (Intake Air Temperature) sensor.

I have an old MAF thread on here somewhere as I had to replace the one that was on our car. I'll see if I can dig it up.

Has the existing MAF been cleaned? Is it modified? How about a vacuum leak? The PCV hose on the side of the throttle body is notorious for cracking. Also, a dirty throttle body or IAC (Idle Air Control) valve can cause the symptoms you have described.

**wssix** · 04-24-2011, 12:01 PM

I was going through this site and found an old post I made last September, I havnt been able to log on to this website since, Until now, I just bought a new computer and donated my old one to the museum as an artifiact. Members on this site posted some help that I was never able to view until now and I wish I could have seen it, would have helped out huge.

Thanks for you reply pajeff02,

The existing MAF has been cleaned with no results. Also, if I unplug the MAF there is no difference in the way it runs. Ive checked for cracks and leaks and so far have not ran accross any. I aslo cleaned the IAC last summer and used a can of cleens in the throttle body, non of which have helped.

**pajeff02** · 04-24-2011, 04:25 PM

Here is the MAF thread: http://www.ls1.com/forums/showthread.php?t=113122

Any codes being set?

**wssix** · 04-25-2011, 09:30 AM

I did get some 02 sensor codes.

Thanks for digging up that thread PaJeff, it was very helpful.

I think I have been confused all along. Are all the MAF's the same outer size, almost 4" and its the inner bore diameter that is either 75mm or 85mm? I assumed that was the inlet size so when I measured up to my car I was scratching my head

Would it be OK to put the factory stock maf back on without problems?

Thanks guys!

**godless-phoenix** · 04-25-2011, 09:50 AM

if you have 02 sensor codes, then replace the bad o2 sensors

**wssix** · 04-25-2011, 10:07 AM

lol good point, on the to-do list.

Anyways, this might make it easier for everyone, some pictures!

Is this a MAF that should be on this car?

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Here is a link to one I a looking at on Amazon,

[ame]http://www.amazon.com/Delphi-AF10043-Mass-Flow-Sensor/dp/B000CGFHBY/ref=au_pf_pfg_s?ie=UTF8&Model=Firebird%7C595&n=156 84181&s=automotive&Make=Pontiac%7C52&Year=2001%7C2 001&newCar=1&carId=001[/ame]

And here is the one I bought,

[ame]http://www.amazon.com/Delco-213-3457-Mass-Airflow-Sensor/dp/B000IYTANQ/ref=sr_1_1?ie=UTF8&s=automotive&qid=1303754778&sr= 1-1[/ame]

Should I buy the Delphi one now???

Sorry, but thanks again

**pajeff02** · 04-25-2011, 10:24 AM

There are actually a couple of MAF's out there that will fit, but the calibration may not be correct for your PCM. I think the only way to tell is to compare the P/N to someone who is running a stock MAF on their car. Mine is buried in a box somewhere right now, but I think I may have posted it in the MAF thread.