Did the MAF twist and it was a sucess!

UPDATED AT POST #7. IT DID NOT WORK WELL IN COLD WEATHER.



For years, I have tried to figured out a way to delete the EGR on our 1999.5 A4 ALH Jetta without getting a code and without getting the ECU re-mapped. I turned the EGR rate all the way down with the vag-com better than stock, but not totally off. There was a thread going that said that that wasn't the best and you could loose some performance and MPG's. That really did it for me.

I did a search and found out the MAF twist deal.

It seemed simple enough, but I was doubtful. Decided to give it a shot and try it. First I pulled the vacuum hose off the EGR valve and plugged it with a wire nut. I removed the two "tamper proof" screws with a small pair of pliers.(not so "tamper proof" huh? ) Then I hooked up the vag-com and twisted the maf until requested and actual were very close together. I know I should dremel the housing and reinstall some other screws, but it seemed pretty tight and there isn't any pressure in the air box. So I said heck with it and took it for a drive. Power is about the same. Maybe a very slight bit of turbo lag, but nothing that noticeable. It might been there before and I just notice it because I am looking for it. The one thing that was noticeable with the lack of the check engine light for the EGR valve. After a hundred or so miles the ECU has yet to figure out the EGR is disconnected. This is awesome!! Now I can rip out all that egr cooler crap outta there.

As of the time of this post, there is no screws in the MAF and it hasn't moved a bit. I know, I should put screws in it. Just gotta dremel the MAF and haven't has time to do it.

The critical thing is that you NEED A VAG-COM to do this mod!!! DO NOT ROTATE YOUR MAF UNLESS YOU HAVE SOME WAY OF MEASURING THE MAF REQUESTED VS. ACTUAL!!!!!!!

If you want more info on this mod, do a search for "maf twist" and you can read all about it.

Disclaimer: Bypassing any emission devise on your car is illegal so this mod if for "off road use only" Do the maf twist at your own risk.

Is nobody interested in this mod? Weard, because I know a lot of people want to disable their EGR without getting a code.

Its good to hear a success story.. perhaps link to your thread in the original one and NARF will start a list of successes so this gets more attention.

Good job on using the proper tools (VCDS) to make sure you aren't over or underdoing it.

turbocharged798 said:

Is nobody interested in this mod? Weard, because I know a lot of people want to disable their EGR without getting a code.

Click to expand...

Most people do this via software.

oilhammer said:

Most people do this via software.

Click to expand...

ya software, thats why i was'nt all hard....

turbocharged798 said:

For years, I have tried to figured out a way to delete the EGR on our 1999.5 A4 ALH jetta without getting a code and without getting the ECU re-mapped. I turned the EGR rate all the way down with the vag-com better than stock, but not totally off. There was a thread going that said that that wasn't the best and you could loose some performance and MPG's. That really did it for me.

I did a search and found out the MAF twist deal.

It seemed simple enough, but I was doubtful. Desided to give it a shot and try it. First I pulled the vacume hose off the EGR valve and plugged it with a wire nut. I removed the two "tamper proof" screws with a small pair of pliers.(not so "tamper proof" huh? ) Then I hooked up the vag-com and twisted the maf until requested and actual were very close together. I know I should dremel the housing and reinstall some other screws, but it seemed pretty tight and there isn't any pressure in the air box. So I said heck with it and took it for a drive. Power is about the same. Maybe a very slight bit of turbo lag, but nothing that noticeable. It might been there before and I just notice it because I am looking for it. The one thing that was noticable with the lack of the check engine light for the EGR valve. After a hundred or so miles the ECU has yet to figure out the EGR is disconnected. This is awsome!! Now I can rip out all that egr cooler crap outta there.

As of the time of this post, there is no screws in the MAF and it hasn't moved a bit. I know, I should put screws in it. Just gotta dremel the MAF and haven't has time to do it.

The criticle thing is that you NEED A VAG-COM to do this mod!!! DO NOT ROTATE YOUR MAF UNLESS YOU HAVE SOME WAY OF MEASURING THE MAF REQUESTED VS. ACTUAL!!!!!!!

If you want more info on this mod, do a search for "maf twist" and you can read all about it.

Disclaimer: Bypassing any emission devise on your car is illegal so this mod if for "off road use only" Do the maf twist at your own risk.

Click to expand...

Can you tell me the procedures on how to use the vagcom to find out the amount of air passing through the sensor? thanks

It doesn't work in cold weather as I found out so I put the maf back to where it was and re-connected the EGR. It kept throwing EGR codes.

Later on, the car started to run like crap with the EGR connected. Not sure why, but I think the N75 may be shot.

Either way I will probably just un-plug the check engine light wire in back of the cluster for now or I might get a chip tune and be done with it.

As for what I did, I just logged MAF actual vs. requested in the measuring blocks and brought the lines together.

turbocharged798 said:

It doesn't work in cold weather as I found out so I put the maf back to where it was and re-connected the EGR. It kept throwing EGR codes.

Later on, the car started to run like crap with the EGR connected. Not sure why, but I think the N75 may be shot.

Either way I will probably just un-plug the check engine light wire in back of the cluster for now or I might get a chip tune and be done with it.

As for what I did, I just logged MAF actual vs. requested in the measuring blocks and brought the lines together.

Click to expand...

Here the weather still hot 80-90's.. When i use the vag-com i read: engine speed:903rpm/min, MAF (specified): "410.0mg/str"(230-370mg/H..I guess thats what it should be..) and MAF (actual)"445.0mg/str"(not stable)(230-370mg/H)... Try to rotate the sensor both sides and does not get lower than that... I need help!!! I can not put the egr cooler back because its bad.. it was contaminating my antifreeze...

That's odd, the actual air should drop right away once you start to rotate the MAF in it's housing.

Maybe your MAF is bad?

You may have the newer style housing that cannnot be rotated too. User Narfblast has a writeup on it.

turbocharged798 said:

That's odd, the actual air should drop right away once you start to rotate the MAF in it's housing.

Maybe your MAF is bad?

You may have the newer style housing that cannnot be rotated too. User Narfblast has a writeup on it.

Click to expand...

well i cut it so that could rotate.. its the style that has the middle with smaller squares.. the numbers move but just up like 440 to 500s but never lower than that, if i remove the sensor out of the housing it drops to 200 300s, so i guess the sensor its working fine.. any ideas?

For what it is worth there is another, simple way to delete the EGR without doing the "MAF Twist" or paying for a specific tune.

Unplug the EGR actuating solenoid. Use that circuit to power a SPDT switch (Relay terminals 85 & 86). You can either splice in the the wires or if there is a U-Pull-it type salvage yard it is possible to find a relay or sensor off one of those cars. Gut it out and utilize the "D" type connector to solder the wires to the relay and plug into circuit. (This is what I did).

Locate the wire on the MAF plug closest to the engine side. On a TDI that would be wire #4. It is usually twisted around the adjacent #3 wire in the wiring to the connector. Cut the wire and connect one side to terminal 30 on the relay. On the other wire you will make a "Y" connection. On side will connect to relay terminal 87a. On the other side add a resistor (I used a 1/2w 5.6K ohm resistor) and connect to relay terminal 87.

By doing this when the EGR solenoid is de-energized the MAF will read as normal. When the EGR solenoid circuit is energized the relay will energize and the added resistance to the MAF circuit will be seen by the ECM as a lower air flow reading same as if the EGR was open.

I was going to get an adjustable Potentiometer and dial in the resistance so that the adjusted "actual" reading would match the requested reading. I used a 5.6K ohm resistor as that is what I had readily available and it is working, i.e., no CEL.

Watching the graph while testing the EGR in VCDS it would appear as the EGR was opening & closing normally. The air flow reading would drop when the relay was energized and jump back up to actual when de-energized.

Total cost to do this was less than $10.