maf screen removal on the na3800 series 2

[tb3]

This is a question concerning my 04 lesabre with a normally aspirated 3800 series 2 engine. figured this section would be the best suited.

I just removed the throttle body to clean up the carbon build up around the blade (it was sticking (annoying). i had to damage the screen to get to the throttle body (yes, i did remove the circlip first), it was just really stuck in there super tight. I tried to gently use the butt end of a wooden handle but no luck.
I don't have another screen to put in till I order a replacement. So I just put everything back together without the screen, and the car runs fine and isn't throwing any codes.
question is, do i even need to buy another? will this mess up my maf readings anyway even tho theres no codes?

tia

 

[xtremexnyc]

Throttle Body Screen Removal

ZZ Performance

 

[EyesofThunder]

....

 

[tb3]

10-15% flow increase? not that I'm really concerned about performance with this car. hmm... guess i'll just leave it out and keep a eye on my idle and fuel milage.

thanks xtremexnyc

 

[EyesofThunder]

I would like to see the flow bench they use to get that....very dubious on 10-15%.....

2-5% maybe.... But not enough to outweigh the negative effects of an out of calibrated MAF....

 

[tb3]

agreed. did some more research, and changed my mind once again. (big surprise ).

heres a guy that did some with and without installed screen data.

MAF Screen or No-Screen? Preliminary results inside... - Cadillac Owners Group

i'm going to find a new one to put back in asap

 

[kshef]

I wouldn't worry about it too much unless you notice start up or driveability problems.

I've got a couple extras lying around if you need one...

 

[tb3]

no start up or idle/driveability problems so far. i can feel a slightly noticeable more pep at lower rpm range.

however, whats got me boggled is that I'm now getting a full mpg increase.

i know, shouldn't be to upset with that, but, i'm never that lucky.

the car just hit 100,000, and has never given me a problem. the onboard message center computer thingy, has always showed 28.5 for my average mpg. even when i reset it, it still came down to the same new number of 29.7, and thats after about 200 miles of driving. ac is on 95% of the time, tire pressures are the same, no change in driving habits, etc.. coolant temp hasn't gone up.

anybody have any theories on this? i ought to research it when I have more time i guess.

 

[mikeb]

Removing the screen was a common thing among 3.3L grand am owners, used to be one. Nobody was able to get any discernable performance or mileage gain. Cleaning the orifice and blade on the throttle body is where you are getting your mpg increase. Another trick that actually works is hosing down your MAF sensor with brake clean. They gather dirt / carbon over time and don't send the computer the precise reading they should. Doesn't gain any performance just restores a little that you may have lost.

 

[tb3]

interesting.

and how does cleaning up the throttebody and blade help mpg? (and it was pretty dirty on the intake manifold side). I spent about 30 minutes using a mild scotch brite and brake cleaner but everything looked new when I finished. (didn't spray any of the sensors of course)

 

[mikeb]

All the crud that deposits there creates a small restriction / turbulence. Not to mention it doesn't allow the blade to properly do its job. With enough debris in the way it will not close all the way and may stick when you apply the throttle. Just having the throttle blade stick is enough to lose some mileage.

 

[murphinator]

my screen has been removed for over 50k since I installed my zzp stage 1 tb that came without it- no ill effects here allthough it is an often debated item........

 

[Torque Overhaul]

It also sometimes depends what year your car is. I have a ZZP stage 1 TB and tried running without the screen as soon as I did it throw a code. Same thing with the stock TB. Put it back in clear the code it was fine. Decided to try again a month later, it did the same thing. At least with the GTP's there have been people with 97/98's that attempted doing this and the PCM ended up throwing codes. As far as leaving it out. 99+ guys no issues take it out and it never sets a code. It's not going to hurt anything, the screen is just there to straighten the air flow when entering the TB. Some cars need it other's don't.

 

[tb3]

that was basically the conclusion i came to. being how the 3800 engine itself was put into a number of differant models,... i would think it would depend on how effective the straight flow through the air cleaner intake system right before the maf sensor is,.. which can very from model to model. apperantly on the lesabre models, its pretty good being i'm still screenless with no problems. mpg has settled down to 29.5 over the last couple thousand miles and stayed there.