I made a switch to emulate the EGR. I measured between 1.5 and 3V coming out of the MAF, at 22 to 50 microamps. I installed a series 1k ohm resistor. After that, I installed a parallel (to the resistor only), normally closed, vacuum actuated switch on the EGR vacuum line. So when the EGR line has no vacuum, MAF senses normal voltage and current. Otherwise, it senses ~2% less. Tried it first this morning, more power, but less in the afternoon. No CEL this time so far. Great explanation.
can you do explain how does the air circulate when you block the egr? do we block it after the EGR cooler or before? where is the turbo situated on your skech
Thanks NARFBlast! Good explanation! Believe it or not, without reading anything, I figured that the system had to work as you describe. When I found there was no EGR flow sensor (e.g., a differential pressure sensor), I figured that flow had to be calculated from other parameters, MAP, displacement, engine speed, IAT. I twisted the MAF down from about 15 to 12 and still have EGR insufficient flow. Just set it to 10 and we'll see if that holds off the code. Isn't IAT also relevant to MAF?
Hi, thanks for this amazing explanation. I did the egr delete on my alh and left the egr operating and put blanks on the egr valve and removed the cooler and blocked off the exhaust. Is there any way to keep the cel off without using more fuel? What are the details about your idea of the maf twist? Would that make your engine use more fuel?
Very interesting, how do we know for certain that the soul purpose for the maf is to work in conjunction with the egr system. Is it not possible that the maf is assisting with further engine management functions?
The MAF sensor tells the ecu how much air flow is coming into the plenum so the ecu can adjust the fuel flow in the correct amount. All this gizmo appears to be is an adjustable air bleed. I don't think it would work but I am not postive . Also the ecu uses the MAP sensor to read Manifold Absolute Pressure and the O2 sensors to to monitor the egr valve.
Dumb question: why not block off the pipe coming from the exhaust and then install an air filter on the EGR side? That way the EGR can open, draw in air and the ECU has no problems because it doesn't know the air being drawn in is filtered fresh air.
Sounds logical to me. My EGR has been deleted (blocked vac line) for a year now. getting 47.9mpg @ 65mph, automatic transmission and 2" lift w/205-70-16" tires. Will perform "twist" now to turn off the CEL. Have already milled (dremel) security post from center of torx screws. Thanks!
HI.great demo of how system works,,, thank you. HOWEVER, I have a situation whereas the engine is being over fueled and causing a mis and other issues, now it does run SOOO much better with MAF disconnected, so I thought I'd found the issue the MAF ordered a replacement and reconnected, still the same over fuel ! Having watched your video can I assume that the most likely cause now is either possibly my MAP sensor OR faulty EGR valve ??. I assume by disconnecting the MAF I have removed that sensor and the ecu has gone to some kind of default or taking its measurements by other means ? By the way the car is more eco and runs so much better with MAF disconnected. THOUGHTS please
I had the same problem with the MAF connected. When I bought the 03 ALH three years ago, the MAF was disconnected. When I connected it, the engine barely ran at all. So, I disconnected the MAF. I bought a brand new MAF and installed it. I had the same problem. My 03 ALH has been running fine for the last three years and getting good fuel mileage without using the MAF. I suspect that my EGR system is not working properly and by connecting the MAF, the engine doesn't have the proper air/fuel ratio as commanded by the ECU. Without the MAF connected, the ECU seems to control the engine just fine. Any thoughts? Also, last winter I inadvertently left my block heater plugged in for several days when the weather got warmer. Since then, my coolant reservoir empties after not driving the car for several days at a time. When I drive the car, the coolant reservoir stays full. It only empties, when the car is not being driven for a few days at a time. I have not found the source of the leak and don't see any fluid on the ground. I suspect that the coolant may be leaking into the exhaust side of the EGR cooler and being burned off by the exhaust system. I'll have to take it apart the EGR system to see if I am right or not. I'm really not liking this entire EGR system at all and would like to remove it and all of it's issues.
Thanks, Yeah I got a little bit of a suction sound no engine code, so when the EGR was removed, manifold is clean so is the EGR, the suction sound stopped. so it must be the egr cooler that has a whole ton of buildup. thanks!
So, what your saying is that if someone wanted to delete their EGR, they could block off the EGR exhaust port and leave the intake side of the EGR open to ambient air with a separate filter?
Update... I performed the MAF Twist a second time and set it down lower, to about 10 GR/SE. This has kept the Check Engine Light off for a couple of tanks of fuel now and allowed me to pass our state safety inspection. I had previously cleaned out my intake manifold and installed the Diesel Geek race pipe (EGR bypass) which caused the EGR insufficient flow problem in the first place.
Alright. Good explanation and good theory. I understand your logic behind it. I have one question for you. If for example I have performed an EGR delete it cannot pull exhaust gas back through the intake. Agreed?? Well, if you perform a MAF twist, like so in your MAF twist video, it will change the G/S reading across the MAF. That's great and all, but even if it's reading lower than 16 G/S, it should still see a drop when EGR is demanded by the ECU. So, my question to you is, how can you fool the ECU by dropping the G/S across the MAF if it's dropped before the ECU even calls for EGR? In theory, if say it's at 10 G/S at an idle after the twist, it should still see a drop from that when the ECU calls for EGR. Please clarify that for me. I'm not arguing because it obviously works to an extent. I just want a logical explanation as to how that fools it.
Hi Mr Blast, I have a B5.5 VW Passat TDI AWX 130 bhp now. My old Passat was TDI 115 bhp and although having done 235000 miles still gave me over 60mph on a long run. I have been told to delete the EGR valve on my AWX 130bhp engine to give me better economy as per my old Passat, is this a waste of time and money ? I have looked inside the EGR and its quite sooty not a good for air flow I would say, it must be the same inside the inlet manifold, hey but what do I know ? I'm Just an ancient biker who understands old lumps of machinery.. :0) Cheers Mate.
If race cars do not have them they are not efficient. Egr valves are great for the car companies because they lower emissions and also carbon up the engines which is part of their planned obsolescence. People got wise to it so now they do the same thing with cam timing by increasing valve overlap.
I made a switch to emulate the EGR. I measured between 1.5 and 3V coming out of the MAF, at 22 to 50 microamps. I installed a series 1k ohm resistor. After that, I installed a parallel (to the resistor only), normally closed, vacuum actuated switch on the EGR vacuum line. So when the EGR line has no vacuum, MAF senses normal voltage and current. Otherwise, it senses ~2% less. Tried it first this morning, more power, but less in the afternoon. No CEL this time so far.
Great explanation.
can you do explain how does the air circulate when you block the egr? do we block it after the EGR cooler or before? where is the turbo situated on your skech
Great information, and quality drawing as well!
Thanks NARFBlast! Good explanation! Believe it or not, without reading anything, I figured that the system had to work as you describe. When I found there was no EGR flow sensor (e.g., a differential pressure sensor), I figured that flow had to be calculated from other parameters, MAP, displacement, engine speed, IAT. I twisted the MAF down from about 15 to 12 and still have EGR insufficient flow. Just set it to 10 and we'll see if that holds off the code. Isn't IAT also relevant to MAF?
Hi, thanks for this amazing explanation. I did the egr delete on my alh and left the egr operating and put blanks on the egr valve and removed the cooler and blocked off the exhaust. Is there any way to keep the cel off without using more fuel? What are the details about your idea of the maf twist? Would that make your engine use more fuel?
@ttmike42 great point. is it doable in terms of space and all?
Upon further consideration and research it wouldn't work. It would basically end up as a boost leak.
Thanks for this. Please keep it uploaded. Great info.
Very interesting, how do we know for certain that the soul purpose for the maf is to work in conjunction with the egr system. Is it not possible that the maf is assisting with further engine management functions?
The MAF sensor tells the ecu how much air flow is coming into the plenum so the ecu can adjust the fuel flow in the correct amount. All this gizmo appears to be is an adjustable air bleed. I don't think it would work but I am not postive . Also the ecu uses the MAP sensor to read Manifold Absolute Pressure and the O2 sensors to to monitor the egr valve.
Dumb question: why not block off the pipe coming from the exhaust and then install an air filter on the EGR side? That way the EGR can open, draw in air and the ECU has no problems because it doesn't know the air being drawn in is filtered fresh air.
Good question wish I knew
Sounds logical to me. My EGR has been deleted (blocked vac line) for a year now.
getting 47.9mpg @ 65mph, automatic transmission and 2" lift w/205-70-16" tires.
Will perform "twist" now to turn off the CEL. Have already milled (dremel) security
post from center of torx screws. Thanks!
sierraromeo did the twist lower your mpg?
HI.great demo of how system works,,, thank you. HOWEVER, I have a situation whereas the engine is being over fueled and causing a mis and other issues, now it does run SOOO much better with MAF disconnected, so I thought I'd found the issue the MAF ordered a replacement and reconnected, still the same over fuel ! Having watched your video can I assume that the most likely cause now is either possibly my MAP sensor OR faulty EGR valve ??. I assume by disconnecting the MAF I have removed that sensor and the ecu has gone to some kind of default or taking its measurements by other means ? By the way the car is more eco and runs so much better with MAF disconnected. THOUGHTS please
If you disconnect the MAF sensor the engine will only run in the closed loop mode. Ie ( RICH )
I had the same problem with the MAF connected. When I bought the 03 ALH three years ago, the MAF was disconnected. When I connected it, the engine barely ran at all. So, I disconnected the MAF. I bought a brand new MAF and installed it. I had the same problem. My 03 ALH has been running fine for the last three years and getting good fuel mileage without using the MAF. I suspect that my EGR system is not working properly and by connecting the MAF, the engine doesn't have the proper air/fuel ratio as commanded by the ECU. Without the MAF connected, the ECU seems to control the engine just fine. Any thoughts?
Also, last winter I inadvertently left my block heater plugged in for several days when the weather got warmer. Since then, my coolant reservoir empties after not driving the car for several days at a time. When I drive the car, the coolant reservoir stays full. It only empties, when the car is not being driven for a few days at a time. I have not found the source of the leak and don't see any fluid on the ground. I suspect that the coolant may be leaking into the exhaust side of the EGR cooler and being burned off by the exhaust system. I'll have to take it apart the EGR system to see if I am right or not. I'm really not liking this entire EGR system at all and would like to remove it and all of it's issues.
Hi NarfBlast. .. question. Does the EGR cooler connection to the EGR ever get carbon buildup?
+Sones S Yes, that could reduce EGR flow from the exhaust system, which would cause a P0402 EGR Excessive flow (at the MAF) code on this engine.
Thanks, Yeah I got a little bit of a suction sound no engine code, so when the EGR was removed, manifold is clean so is the EGR, the suction sound stopped. so it must be the egr cooler that has a whole ton of buildup. thanks!
So, what your saying is that if someone wanted to delete their EGR, they could block off the EGR exhaust port and leave the intake side of the EGR open to ambient air with a separate filter?
Pete Kraft this would create a turbo pressure leak now I think.
Update... I performed the MAF Twist a second time and set it down lower, to about 10 GR/SE. This has kept the Check Engine Light off for a couple of tanks of fuel now and allowed me to pass our state safety inspection. I had previously cleaned out my intake manifold and installed the Diesel Geek race pipe (EGR bypass) which caused the EGR insufficient flow problem in the first place.
Herman Munster have you noticed using more fuel after the twist?
So you can’t just delete the egr because you will get a code ?
I have an off-road jetta tdi that has a egr delete done but I have a service light on for the past 4 years. How to correct this issue?
Pontala Vasconcellos Moreira get a tune
Aaron Garcia does the tune keep the fuel consumption low?
Alright. Good explanation and good theory. I understand your logic behind it. I have one question for you. If for example I have performed an EGR delete it cannot pull exhaust gas back through the intake. Agreed?? Well, if you perform a MAF twist, like so in your MAF twist video, it will change the G/S reading across the MAF. That's great and all, but even if it's reading lower than 16 G/S, it should still see a drop when EGR is demanded by the ECU. So, my question to you is, how can you fool the ECU by dropping the G/S across the MAF if it's dropped before the ECU even calls for EGR? In theory, if say it's at 10 G/S at an idle after the twist, it should still see a drop from that when the ECU calls for EGR. Please clarify that for me. I'm not arguing because it obviously works to an extent. I just want a logical explanation as to how that fools it.
Phillip Wilson the ECU is not that smart, and it has wide tolerances so I think that is why we can get away with this.
Awesome! Thanks for sharing!
thank you for this video
thanks for sharing. love the ALH
Hi Mr Blast, I have a B5.5 VW Passat TDI AWX 130 bhp now. My old Passat was TDI 115 bhp and although having done 235000 miles still gave me over 60mph on a long run. I have been told to delete the EGR valve on my AWX 130bhp engine to give me better economy as per my old Passat, is this a waste of time and money ? I have looked inside the EGR and its quite sooty not a good for air flow I would say, it must be the same inside the inlet manifold, hey but what do I know ? I'm Just an ancient biker who understands old lumps of machinery.. :0) Cheers Mate.
I don't know about anything about those engines. My EGR system stopped working and I can't be bothered to fix it propely.
If race cars do not have them they are not efficient. Egr valves are great for the car companies because they lower emissions and also carbon up the engines which is part of their planned obsolescence. People got wise to it so now they do the same thing with cam timing by increasing valve overlap.
0:53 TDI = Turbo Diesel Injection. So, whenever someone talk about TDI engine that makes it obvious that he's talking about a diesel engine
TDI stands for Turbocharged direct injection
Super! Glad it worked for you!