How to remove the BOSCH MAF screen on the 2.7T engine.

Singletrack · 10-25-2002, 08:35 PM

So why do this? Well, several other people's tests have shown that it both eliminates a pressure drop in front of the turbo as well as increasing airflow a small amount. I wrote this message up to help people with the process, not to debate this issue : ) So do a search and check out the past posts on the same topic.

First off, here is a shot of the left side of the engine with the cover removed. The MAF housing is the thing with the adaptor plugged into it. Remove the plastic clips on the three hoses running over the airbox so that you have more room to work.

The MAF housing has two clamps that need to be undone before it can be removed. Here is a picture of the one on the left side. As you can see it is sort of under the three hoses we have previously moved.

Here is a shot of the right side clamp.

Here is an overhead shot of both clamps.

Once you undue the clamps, the MAF housing will pull straight out towards the engine block. Be careful, as there is a small rubber ring to help seal the connection that will pull out as the housing is removed. It is shown in the foreground of this picture.

Then you must unscrew the clamp on the right downstream side of the MAF to fully remove it from the car. Don't forget to unplug the wire running to the sensor : )

Here is a picture of the plastic flow straightener and the screen behind it that we will be removing. REPEAT: We are removing the metal screen, not the plastic flow straightener.

A shot from the inside.

Next you will need a security torx 10 bit to remove the sensor from the housing. You can't always find them in stores, but you can order them online from a number of places.

Put the MAF in a plastic bag. Make sure not to touch the sensor itself.

This is a crappy picture of me getting the tearing started on the screen. You can start it out with a small screwdriver.

Then finish it off by pulling out with some needle nose pliers.

Some have popped out the the plastic flow straightener and removed the metal screen without damaging it. It's up to you which way you would like to do it.

Just reverse the process of removal to put it back in minus the metal screen.

Do this at you own risk, and if you screw up don't blame me : )

-st

GIACUser · 10-25-2002, 10:29 PM

Could you tell a diff?

Singletrack · 10-25-2002, 10:44 PM

Could be placebo effect, but I really think it did make a difference. Should take some time for the ECU to adapt to the airflow increase as well I believe.

-st

Milpitas2.7T · 10-26-2002, 12:41 AM

I have a Bosch MAF that has been de screened already. You just borrow it plug yo own stuff in and off you go. Will let folks borrow for a week if your local to me in NorCal.

Singletrack · 10-26-2002, 06:11 AM

Have you done any data logging?

-st

AudiByNature · 10-26-2002, 07:50 AM

Will this void the warranty? What would happen if you left the sensor connected (at least for service visits)?

(sorry if these are unbelievably idiotic questions)
I sure hope Stoney doesn't read this ;-)

TIA

oops · 10-26-2002, 08:09 AM

AudiByNature · 10-26-2002, 08:21 AM

protect it while you're working?

GIACUser · 10-26-2002, 08:51 AM

Bollinger · 10-26-2002, 08:52 AM

Yes, this modification will void your warranty for problems it causes. What problems will it cause? Personally, I can't envision any. Perhaps the person who put the screen there in the first place knows.

10-25-2002, 08:35 PM	#1
Singletrack AudiWorld Super User Account #: 25380 Join Date: Sep 2001 Posts: 16,037	How to remove the BOSCH MAF screen on the 2.7T engine. So why do this? Well, several other people's tests have shown that it both eliminates a pressure drop in front of the turbo as well as increasing airflow a small amount. I wrote this message up to help people with the process, not to debate this issue : ) So do a search and check out the past posts on the same topic. First off, here is a shot of the left side of the engine with the cover removed. The MAF housing is the thing with the adaptor plugged into it. Remove the plastic clips on the three hoses running over the airbox so that you have more room to work. The MAF housing has two clamps that need to be undone before it can be removed. Here is a picture of the one on the left side. As you can see it is sort of under the three hoses we have previously moved. Here is a shot of the right side clamp. Here is an overhead shot of both clamps. Once you undue the clamps, the MAF housing will pull straight out towards the engine block. Be careful, as there is a small rubber ring to help seal the connection that will pull out as the housing is removed. It is shown in the foreground of this picture. Then you must unscrew the clamp on the right downstream side of the MAF to fully remove it from the car. Don't forget to unplug the wire running to the sensor : ) Here is a picture of the plastic flow straightener and the screen behind it that we will be removing. REPEAT: We are removing the metal screen, not the plastic flow straightener. A shot from the inside. Next you will need a security torx 10 bit to remove the sensor from the housing. You can't always find them in stores, but you can order them online from a number of places. Put the MAF in a plastic bag. Make sure not to touch the sensor itself. This is a crappy picture of me getting the tearing started on the screen. You can start it out with a small screwdriver. Then finish it off by pulling out with some needle nose pliers. Some have popped out the the plastic flow straightener and removed the metal screen without damaging it. It's up to you which way you would like to do it. Just reverse the process of removal to put it back in minus the metal screen. Do this at you own risk, and if you screw up don't blame me : ) -st __________________ 2008(9?) S5 - ordered 3/29/08 2004 Subaru Impreza WRX STi 2000 A6 2.7T - Sold "On the run from Johnny Law; ain't no trip to Cleveland."

10-25-2002, 10:29 PM	#2
GIACUser Junior Member Account #: 23907 Join Date: Aug 2001 Posts: 1,119	Nicely done, thanks! A great addition for Stoney collection. Could you tell a diff?

10-25-2002, 10:44 PM	#3
Singletrack AudiWorld Super User Account #: 25380 Join Date: Sep 2001 Posts: 16,037	Thanks! Actually, it did seem to make an immediate difference with throttle response. Could be placebo effect, but I really think it did make a difference. Should take some time for the ECU to adapt to the airflow increase as well I believe. -st __________________ 2008(9?) S5 - ordered 3/29/08 2004 Subaru Impreza WRX STi 2000 A6 2.7T - Sold "On the run from Johnny Law; ain't no trip to Cleveland."

10-26-2002, 12:41 AM	#4
Milpitas2.7T Elder Member Account #: 6383 Join Date: Jun 2000 Posts: 25,962	If your norcal and want to test one already modified, I can assist I have a Bosch MAF that has been de screened already. You just borrow it plug yo own stuff in and off you go. Will let folks borrow for a week if your local to me in NorCal. __________________

10-26-2002, 06:11 AM	#5
Singletrack AudiWorld Super User Account #: 25380 Join Date: Sep 2001 Posts: 16,037	What a nice offer! : ) So what are you running for a MAF right now if I may ask Milpitas? Have you done any data logging? -st __________________ 2008(9?) S5 - ordered 3/29/08 2004 Subaru Impreza WRX STi 2000 A6 2.7T - Sold "On the run from Johnny Law; ain't no trip to Cleveland."

10-26-2002, 07:50 AM	#6
AudiByNature Audiworld Junior Member Account #: 36751 Join Date: May 2002 Location: Atlanta, GA Posts: 528	Not trying to start a debate, and this is probably a very stupid question... Will this void the warranty? What would happen if you left the sensor connected (at least for service visits)? (sorry if these are unbelievably idiotic questions) I sure hope Stoney doesn't read this ;-) TIA __________________ 2007 Q7 4.2 Premium S-Line - Daytona Gray, black interior, 2009 Q5 3.2 Premium Plus - Ice Silver/Black interior, 19" rims. Gone, but not forgotten: 2002 A6 2.7T Tiptronic - **** that was a fun car for a 4 door heavy sedan 2005 Touareg V8 - what a beast - great for off-roading. It will be mine, oh yes, it will be mine: 2010 S5 Cab, white

10-26-2002, 08:09 AM	#7
oops Junior Member Account #: 3941 Join Date: Apr 2000 Posts: 1,120	he only removed the screen. everything else went back on as it was. __________________ "I have to quit working so much, its eating up my Audiworld time." Please use the classifieds ---- "quattro" 'nuff said ----

10-26-2002, 08:21 AM	#8
AudiByNature Audiworld Junior Member Account #: 36751 Join Date: May 2002 Location: Atlanta, GA Posts: 528	So the sensor does go back on? You just put it in the bag to... protect it while you're working? __________________ 2007 Q7 4.2 Premium S-Line - Daytona Gray, black interior, 2009 Q5 3.2 Premium Plus - Ice Silver/Black interior, 19" rims. Gone, but not forgotten: 2002 A6 2.7T Tiptronic - **** that was a fun car for a 4 door heavy sedan 2005 Touareg V8 - what a beast - great for off-roading. It will be mine, oh yes, it will be mine: 2010 S5 Cab, white

10-26-2002, 08:51 AM	#9
GIACUser Junior Member Account #: 23907 Join Date: Aug 2001 Posts: 1,119	Correct... very sensitive piece, a few flecks of crud or oil could really cause problems.

10-26-2002, 08:52 AM	#10
Bollinger Elder Member Account #: 502 Join Date: Mar 2000 Posts: 39,985	yes, and if the dealer finds out you did it, a discussion will certainly ensue Yes, this modification will void your warranty for problems it causes. What problems will it cause? Personally, I can't envision any. Perhaps the person who put the screen there in the first place knows. __________________ -- "Nonconformity? Oh yeah, you're the first 20 something kid I have seen with a Japanese letter tattooed on his arm. You want to be a nonconformist? Buy a pocket protector and get a haircut. The Chinese kids spending 20 hours at a time in the library are the ones who really don't care what you think about them" - Dr. House (fictional character)

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