My base '08 started having a mild hesitation/miss at about 1100-1300 rpms and developed a rough idle about a month ago. Since then it has become more noticeable and seems to affect a wider range of rpm. Also, the throttle response was getting a lot more sluggish and it seemed like I was having to push the pedal in further to keep the car rolling down the road. It felt like soon I'd have to get out and start pushing to help it out.

So, based on past threads I've searched, today I unplugged the MAF. WOW, what a difference! The car is a beast! Throttle response is great. The pedal doesn't have to be pressed anywhere near as far to accelerate quicly. Downshift power is much better. The hesitation/miss is gone. The idle fluctuates but is smoother regardless. Everything is better EXCEPT the shifts are much harder and the car almost thuds into the next gear even under slow acceleration. I've plugged the MAF back in due to this.

So, is it worth trying to clean the MAF or is it just bad and in need of replacement? Will a new MAF result in the car behaving like this? If it does the tranny will not last long. Long shot guess, perhaps disconnecting the MAF results in the tranny ECU not operating normally?? Is there a tranny ECU? Seems like every damn thing in this car has an ECU.

Thanks for any help and info,
Doug

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- 2008 Pontiac Grand Prix - Base - 3800 Series III / NA - ZZP HV3 Insert - K&N Air Filter in stock housing -

weird. i unplugged my maf in my 04 gt and the car would stop itself once it got to 3000 rpms.. the dic showed a message, something about engine power I think, and would not go until I restarted it..

but you could always try cleaning the maf unless you want to take the easy way out and just buy a new one.. they do tend to get a little gunked up sometimes. idk how that will affect it but it won't hurt to clean it

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04 gt2- wizair, 180tstat, 2.5" dp highflow cat, hv3 insert


can mileage be like our post count? once you get over a certain point, you get an upgrade... id like that

Yeah, I disconnected it and the car started up just fine, ran like a champ well past 3000rpm, didn't affect the avg. mpg on the dic on a 20 mile drive home from work, and the exhaust & intake sounded much nicer. If it wasn't for the harsh shifting, I'd say the car is better without. Of course I realize the MAF is necessary for daily use, but I'm just saying it's much nicer than the car has been in the last 6 months I've owned it.

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- 2008 Pontiac Grand Prix - Base - 3800 Series III / NA - ZZP HV3 Insert - K&N Air Filter in stock housing -

I've used CRC MAF Sensor Cleaner and Throttle Body Cleaner on both of my cars, money well spent!

I feel like I'm missing out on something... lol

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04 gt2- wizair, 180tstat, 2.5" dp highflow cat, hv3 insert


can mileage be like our post count? once you get over a certain point, you get an upgrade... id like that

when you pull the plug the pcm goes to a modified fixed tune.
so if it runs better w./o the maf clean it if that dont work try replacing the maf

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Aragorn

New track mod???

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The cleaning of the induction system (MAF, TB, etc.) helps out tremendously. I had my dealer clean mine after my GP was starting to hesitate after I would turn it over from a cold start or even one coming from a warmed-up engine. I wasn't able to finish the one you can do yourself because I was having trouble disconnecting the vaccum hose from my K&N to the bellows, that's why I had the dealer do it. Here's the link below:

do-it-yourself-f12/clean-your-maf-throttle-body-t3899.html

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2004 Pontiac Grand Prix GTP Competition Group

Pulling the plug to the maf would change quite a few settings in the PCM - Including changing your shift pressures ( this is why you feel the hard shifts NOTE: Harder shifts are better due to the clutch/gear bands no longer SLIDE in place but bang into place which does reduce wear and extendes the life the bands but in return you dont have the smooth shifting ). By Unpluging the maf your telling the PCM that there is a issue with a component - In return the PCM will act upon by changing specific settings to counter defective/unpluged component.

-- Mon Sep 06, 2010 11:31 pm --



x2 works wonders!!!!!!!!!!!!!!!!!

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2004 Grand Prix GT AGGRESSOR
PRJ PCM, Custom Exhaust, 180 stat, FWI Custom Intake, DIC upgrade.

I did not know that about auto transmissions, but thinking about how the clutch works in a manual transmission, it makes sense.

Hopefully, I will clean everything out this weekend. Maybe I'll try out my new garage if the concrete floor is cured enough.
-Doug

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- 2008 Pontiac Grand Prix - Base - 3800 Series III / NA - ZZP HV3 Insert - K&N Air Filter in stock housing -

Alright, I cleaned the MAF and cleaned out all of the gunk from the throttle body. The MAF didn't have any noticeable dirt/debris but the throttle body was coated with crap. The car starts a little stronger, the idle is a little smoother, the throttle response is better, but the hesitation problem is still there. And I still don't have anywhere near the throttle response or power that I have when I unplug the MAF.

So, it is a good bet that the MAF is bad and needs replacement or could there still be other culprits? FYI, the hesitation completely goes away when the MAF is unplugged.

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- 2008 Pontiac Grand Prix - Base - 3800 Series III / NA - ZZP HV3 Insert - K&N Air Filter in stock housing -

If the MAF is bad, you should have had a code come up like a p0102 ? I did not realize the car would run with it unplugged, but I guess they do, just not metered correctly. If the car runs and no codes are up then, " Hum " could be something else? I try and use my scanner on everything and if I need the big one I go to a friends and put it on the Snap On Scanner.

Yeah, in theory, a bad MAF should set the check engine light. If you can pull code history, there may be something there. In my opinion, I'd just replace it anyways.

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One Big Ass Mistake America

This was an older post but I figure I'd update it since it has been brought up again. I did clean the MAF and TB with the appropriate cleaners and it made little to no difference. I have never seen a check engine light (except when I unplugg the MAF) but I ended up replacing the MAF with a very cheap used one. The problem persists. My question is whether or not the replacement MAF would result in the same exact performance issues if it was bad as well. I wouldn't be shocked if this MAF was bad too, but wouldn't the car behave at least a little different.

I did Seafoam the car recently (gas tank, crank case, vacuum) and got instant improvements that lasted about 1 week. The car was completely better. There was no hesitation at low RPMs, the idle was much smoother, much more power, and the throttle response was much quicker. I did change the oil and oil filter, but I have not replaced the spark plugs or fuel filter yet. I will do that soon. Although I'm starting to wonder if it may be the regular gas I use. It seemed like the improvements went away once the tank with Seafoam was gone and I filled up again. Of course that could be the fuel filter, but I've read many posts stating how picky these III series engines are sometimes.

-Doug

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- 2008 Pontiac Grand Prix - Base - 3800 Series III / NA - ZZP HV3 Insert - K&N Air Filter in stock housing -

You may need to clean your throttle body then.

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'05 WRX STi- AP Stage 2 tune|Invidia DP|3" Borla XR-1 CBE|TiC super shifter set|DBA 4000 rotors/SS lines|Lots of braces/poly bushings
Sold: 06 Cobalt SS/SC, 99 GTP 245WHP/326 Ft-lbs, 06 R6