UFO mods for diesel EGR Delete

[UFO]

Currently experimenting with the EGR disconnected on my 2001 VW Beetle. I have built an EGR emulator to keep the MAF input to the computer within the range it expects when EGR is commanded. I have retained the factory setting of 270 mg/stroke at idle with the EGR duty between 35% and 75%. This is to keep the EGR code from being set and the computer changing the engine fueling to compensate for the lack of EGR.

I have baselined two fuel tanks of pump diesel with EGR functional, and will be entering those on my fuel log. I am now operating without EGR. The warmup time is significantly affected, and to compensate I have partially blocked off the radiator. I had to trim out more cardboard as I was exceeding the thermostat temperature at the end of my morning drive. Once I have a pair of tanks baselined with this configuration, I will re-enable the EGR and compare to a new baseline retaining the grille block (my current baseline was not done with the block). Then I will probably disable the EGR for good, and make my EGR emulator circuit available to purchase on Ebay, hopefully with good data to backup any mileage improvement claims I can make.

Here are pictures of my grille:




Happy dieseling from the Oil Burner Kartel!

[drmiller100]

For future, on many diesel EGR's you can physically remove the EGR, plug the passages left behind, then plug the wires back into the EGR, and lay the EGR on the intake manifold out of the way.
The computer thinks the EGR is still there, but nothing ever flows anywhere.

Purely for short term testing purposes of course.

[UFO]

The computer measures actual drop in air flow through the MAF with EGR engaged. Only in the most primitive of EGR systems will that approach work, and none of the VW systems. There is no need to remove the valve, you simply have to block the hose, and the valve will remain closed.

[tradosaurus]

I bought a 2000 Mazda Protege LX (1.6L) with 5 spd a month ago. I was planning on cleaning the EGR but noticed it was removed. The pipe from exhaust manifold was removed and the opening plugged. The vacuum line to the EGR sensor was removed but the electrical plug is still in. The EGR valve is removed and I frankly cannot even see where it would have attached to the intake manifold or throttle body.

[NachtRitter]

Would it be simpler to use the VAG-COM to tell the computer to ignore the EGR? Or does that not achieve the same results as what you are trying to do?

[Daox]

Originally Posted by tradosaurus

I bought a 2000 Mazda Protege LX (1.6L) with 5 spd a month ago. I was planning on cleaning the EGR but noticed it was removed. The pipe from exhaust manifold was removed and the opening plugged. The vacuum line to the EGR sensor was removed but the electrical plug is still in. The EGR valve is removed and I frankly cannot even see where it would have attached to the intake manifold or throttle body.

Keep in mind that UFO is doing this on a diesel engine. Most gasoline engines benefit in power, mpg, and emissions from using EGR. In diesels its normally mostly an emissions tool.

[UFO]

Originally Posted by NachtRitter

Would it be simpler to use the VAG-COM to tell the computer to ignore the EGR? Or does that not achieve the same results as what you are trying to do?

IF I had a registered copy of VAG-COM (not the freeware version), I could reduce the EGR but not eliminate it. Judging from the actual MAF values without EGR and what VAG-COM allows you to reduce, all you can do is cut the factory flow by about 40%, 270mg/stroke to 370mg/stroke, and full flow (no EGR) measures about 480mg/stroke. US spec'd EGR flow at idle is truly excessive and ridiculous.

A tuner may be able to reduce that value more so you don't get the CEL, but I don't need a tune and my vehicle is staying factory stock for all outward appearances. A tuner cannot technically remove the EGR either, the vehicle owner/operator must take responsibility for that.

[UFO]

Updated my fuel log, trying to be very consistent in maximizing my mileage, no matter the EGR configuration. Unfortunately the temperatures are warmer now, and the traffic always varies. Hopefully the EGR/no EGR differences will average out over the next two tanks before I revert to the "A" configuration.

It seems quite obvious to me that the dominant element in my fuel mileage is how much biodiesel I am running. The weather the past fall is similar to now, but I am now out of biodiesel, and my mileage really took a hit as soon as I ran out. It looks like I may realize some mileage gain without EGR, but I'll have to see. Since the Scangauge is affected by the different MAF reading with/without the EGR functioning, it renders it useless in making the comparison.

[NachtRitter]

Originally Posted by UFO

A tuner may be able to reduce that value more so you don't get the CEL, but I don't need a tune and my vehicle is staying factory stock for all outward appearances. A tuner cannot technically remove the EGR either, the vehicle owner/operator must take responsibility for that.

Don't have a VAG-COM either, though it seems there are enough folks on TDIClub with one that there might be someone near you willing to help out. But I think I see what you're saying... modifying the settings via VAG-COM wouldn't eliminate the EGR completely, whereas your approach leaves all the hardware in place but doesn't allow the EGR to work.

[oil pan 4]

Originally Posted by UFO

It seems quite obvious to me that the dominant element in my fuel mileage is how much biodiesel I am running.

That is good to know. I used B10 for the first time and had an unusally high mpg number, high enough I threw it out because I figured I made an error some how.