Quick Help: Okay to do !MAF and De-Screen Mod???

Just need a quick answer. Is it safe to remove the restrictions in the MAF housings and de-screen the MAF??? I need to pass California emmision testing if that matters. Won't be any SES lights I hope? Thanks

Let me put it this way : a 2002-3 corvette z06 has a smooth MAF and absolutely no screens STOCK from the factory.

I think I know what you mean, I already started anyways.

Well, you "can" do it and still pass emissions, but there are little wires that if messed up with F up everything, so pretty much do it at your risk. IMO I don't think it's worth it.

I haven't even breathed on the wires in the MAF yet, and I stashed it in the safest place I could find. Nothing will happen to it

I make it a point to not alter precision measurement devices, and I'd suggest that you do the same.

I think it is pointless without tuning.

Having said that, I swear I heard and felt a difference after descreening / porting mine.

:confused:

I screwed my old one up trying to get the coolers out. So I got another one (lucky for $35 from a board member) and left it alone. The screens are easy, and they help. I think. I left my air-cleaner side screen on, because I run without filters at the track. :)

Please at least attempt to use the technical forums first before posting stuff like this in the Lounge. Moving to LS1 Tech.


Craig

Originally posted by Shockwave
Please at least attempt to use the technical forums first before posting stuff like this in the Lounge. Moving to LS1 Tech.


I needed a fast response.

I just descreened mine today cant tell the diff. but they say it supposed to run better. Car Craft Mag. had it in this month mag on LT1 tuning.

Wow this is an old thread...:)

I didn't notice anything either except for a SES code:( But I reset the PCM and is hasn't come on since.

Originally posted by Ferocity02
Wow this is an old thread...:)

I didn't notice anything either except for a SES code:( But I reset the PCM and is hasn't come on since.

It will come on again,

I did this mod, and I had to reset the PCM about 6 times since I did it. It makes the car run too lean.

Descreened on mine. Runs fine. Everyone I know does it.

de-screened mine during the dyno run, gained 3HP. no SES problems.

Originally posted by camaro322hp
de-screened mine during the dyno run, gained 3HP. no SES problems.

you gained 3rwhp from just de-screening your maf? If you just descreen it...it shouldnt throw a code should it? I mean i thought most people have the problems when it comes to porting it.

Originally posted by Eliminator
I just descreened mine today cant tell the diff. but they say it supposed to run better. Car Craft Mag. had it in this month mag on LT1 tuning.

What did the mag say about de-screening it?

Ported MAF Ends & de-screened. Running strong.

Originally posted by CamaroGuy22
you gained 3rwhp from just de-screening your maf? If you just descreen it...it shouldnt throw a code should it? I mean i thought most people have the problems when it comes to porting it.

yeah, i couldn't believe it either. they guy running the dyno said it's pretty normal to gain 2 or 3 rwhp just by pulling the screen. keep in mind that was with the stock lid. and unless you screw up the MAF somehow, you shouldn't throw any codes.

i'll try to find a scanner and get my before and after dyno curves posted. (cos i wouldn't believe it if i were you either!)

Thats a decent gain...looks like i will be de screening mine.

Count me in as another descreened! About 5,000 miles no problems no SES light:bow:

The juice isn't worth the squeeze, or in this case the potential aggrivation. I'd leave it alone.

Originally posted by SSoFAST
The juice isn't worth the squeeze, or in this case the potential aggrivation. I'd leave it alone.

Amen, And if you want your car to run good all of the time then just leave it alone. All it does is fool the computer then when you get into some real hot weather or the gas isn't perfect SPARK KNOCK AND RETARD.
A Z06 MAF may be smooth and without a screen but you can bet your last dollar that GM programmed the computer to run with it that way.
If you have LS1 edit, a MAF translator, or a custom tune then go for it.
Check my sig for stock MAF numbers.:D :D :D

Originally posted by AL SS590 M6
Amen, And if you want your car to run good all of the time then just leave it alone. All it does is fool the computer then when you get into some real hot weather or the gas isn't perfect SPARK KNOCK AND RETARD.
A Z06 MAF may be smooth and without a screen but you can bet your last dollar that GM programmed the computer to run with it that way.
If you have LS1 edit, a MAF translator, or a custom tune then go for it.
Check my sig for stock MAF numbers.:D :D :D

How does descreening it fool the pc? I thought it just gave you more cfm...i really dont know so thats why i am asking.

I read on a website (Raughammer's Pepper was the name but the site won't come up anymore) that it messes up an A4. the computer reads less of a load through the maf and sends a signal to the transmission that there less of a load and over time it will start sliding into gear instead of shifting hard like it should. I had a ported maf and now it just slides into gear. I have been trying to find this site again but no luck.:(

Thanks for the info bud! :)

Originally posted by RS Dragster
Black 1999 Trans Am A4 3.23
SLP Ram-Air H.O. Hood, ZR1 11's all around w/ Nitto's, MTI Clear Lid, Holley Powershot Filter, Smooth Air Bellow, FRA, !EGR, TB Bypass, BMR STB & SFCs, Dynomax Muffler, AfthoughtsAuto Silver Accents, NR White-Faced Guages *290.3rwhp 297.9rwtq*
My 99 TA

1992 Firebird 3.1 (daily driver)
17.125@79



How the hell did you fit 17 x 11's in the front???? Are you sure they aren't 17x9 front and 17x11 rear?

Gaining 3rwhp from removing the screen, I'd be skeptical. 3-5rwhp is common variance between back-to-back pulls without changing anything. Dyno's aren't intended to be that accurate.

Modifying the MAF will cause the tables in the stock PCM to be inaccurate. Long story short, it leans you out, and screws up any PCM calculations which are derived from measuring the incoming airflow. It is correct about the A4's and ported ends (sorry to hear you found out the hard way, MARSTAUT.)

I started with the stock MAF. When my engine hydralocked, the builder installed ported ends. That was fine and dandy, except that it was hard to mail-order tune them. When LS1-Edit came out, the owners found it was difficult to calibrate the tables without actually flowing the MAF ends. I went back to a stock MAF and made the same power as the ported ends, and driveability was better, too.

If I were you, I'd leave it as-is. The 'gains' aren't worth the potential hassle down the road.

I do know that descreening a 98 A4 MAF will cause major problems. It doesn't have the same effect on the other years, but never do it on the 98 A4. I've seen several people try it, and it really screwed things up, but only on a 98 A4

Originally posted by JimMueller
Gaining 3rwhp from removing the screen, I'd be skeptical. 3-5rwhp is common variance between back-to-back pulls without changing anything. Dyno's aren't intended to be that accurate.


agreed, however, here's the sequence: i did 3 pulls first, then pulled the screen, then did 3 more pulls. all 3 pulls with screen removed were higher than any pull with screen in. 3 rwhp was the gain from peak screen in to peak screen out. maybe i didn't gain 3, but there was some gain there to speak of.

i guess all i'm saying is that i gained some power and haven't seen any ill effects from it. but from all the posts i've been reading, maybe it should not be done. maybe i'm one of the lucky few who didn't screw up my MAF doing this mod.

it's hard for me to believe that pulling a screen out would create so many problems, especially when all the screen does is create small micro-turbulences in the air flow. if i wasn't so lazy, i'd grab my fluids book and do a bernoulli equation on it...

I got some non-ported Maf ends but I still need a screen, so if anyone wants to get rid of thiera I'm interested, I would recommend someone with a an M6 to sell thiers and the guys with A4's to put thiers back on.;)

i'd give you mine, but i kind of destroyed it when removing. i'm sure someone else has one in good condition...

Ya, they are hard to get out without breaking.

Well I ported my ends and got codes so I'm going back to stock, just to let ya know :(

I talked to Bryan at PCMFORLESS and he said descreeing shoudlnt cause any problems...but when you port your MAF it makes it very hard to tune..