EGR reduction: update

**diesel dog** · 2nd January 2009, 18:59

A few of us (well,two or three) decided a while ago to restrict EGR on our V6s.First of all I completely blanked the intake and it was fine for a couple of hundred miles until the spanner and EML lights came on!

VX reset the ECU (free) and all was well (I having first removed blanking plate).Having sermised that the EGR is fitted with some sort of sensor (probably exhaust gas temp) we deduced that it would be possible to get away with a reduced EGR rather than a fully deactivated EGR,believing that all that the sensor requires is a heat source and so a hole (13mm dia) was drilled in the blanking plate which allows a very small amount of EGR to flow,but only enough to keep the sensor happy.

In over a thousand miles the car has been OK (barring DMF of course).

It occured to me that owners of DPF'd cars may also want to consider this mod.The reason for the DPFs is that for cars to have the correct amount of NOx reduction (EURO 4) the EGR has to put a greater amount of Exhaust gas into the inlet.This reduces the NOx further,but also increases soot particles,hence the need for the DPF.If you restrict the EGR you will not only have better engine performance and life,but you will also give your DPF an easier life as well.Also,should anything other than soot (which is reduced with this mod) be tested for the MOT in the future the plate (on the V6) takes only minutes to fit or remove.

**Big Sig** · 2nd January 2009, 19:14

I can't remember, but did you take photos of how to locate, remove and refit with this plate in??

**diesel dog** · 2nd January 2009, 19:22

I believe that this http://www.vectra-c.com/forum/showthread.php?t=51953 is the thread that you may be referring to.

Also.http://www.vectra-c.com/forum/showthread.php?t=52983

**ANDY W** · 2nd January 2009, 19:52

Does a Remap which disables the EGR work the same way then ?. As mentioned many times before, I have the Regal EDS Remap and I have the option of 190bhp no EGR and 200bhp no EGR and at the moment I am running the 190 version but this Remap also makes the DPF kick in every 1000 miles to keep everything clean.

**diesel dog** · 2nd January 2009, 20:01

Originally Posted by ANDY W

Does a Remap which disables the EGR work the same way then ?. As mentioned many times before, I have the Regal EDS Remap and I have the option of 190bhp no EGR and 200bhp no EGR and at the moment I am running the 190 version but this Remap also makes the DPF kick in every 1000 miles to keep everything clean.

No.

The remap will shut down the EGR system completely,although some remaps only reduce the duty cycle by maybe not opening the valve quite so much under the same conditions.

If I had a DPF fitted I would not want the EGR working with a remap!

**ANDY W** · 2nd January 2009, 20:05

So is this Remap EGR disabling a good thing or bad then.

**diesel dog** · 2nd January 2009, 20:19

Originally Posted by ANDY W

So is this Remap EGR disabling a good thing or bad then.

It's a good thing.

1.Less Exhaust gas into the inlet means less soot out of the exhaust.
2.Throttle response is better because there is no delay between the diluted (part throttle) EGR mixture and the new (extra load) mixture.
3.No crap is going into the intake (soot,acid,water etc) so longer oil and engine life.
4.Engine power is increased at part throttle (because mixture is not diluted),therefore less throttle to go at the same part throttle speed as with EGR,so improved fuel consumption.

EGR is only there to reduce NOx.

**ANDY W** · 2nd January 2009, 20:29

Just wondering as to what can cause a lumpy idle almost sounding as if it is missing but only on idle. Sorry to change the topic slightly but as said my EGR is disabled but I get this idling problem and its intermitant but doesnt make the car stall or cut out.

**diesel dog** · 2nd January 2009, 20:41

EGR should be shut off at idle anyway,so your problem is elsewhere unless the valve isn't closing fully,but it could be any number of things that are nothing to do with either your map or the EGR system which will normally throw up a fault code if it's not functioning correctly.Obviously if it's been 'mapped out' there will be no codes.

Could be the infamous number three cylinder injector wiring problem.

**benny** · 2nd January 2009, 21:05

Originally Posted by diesel dog

A few of us (well,two or three) decided a while ago to restrict EGR on our V6s.First of all I completely blanked the intake and it was fine for a couple of hundred miles until the spanner and EML lights came on!

VX reset the ECU (free) and all was well (I having first removed blanking plate).Having sermised that the EGR is fitted with some sort of sensor (probably exhaust gas temp) we deduced that it would be possible to get away with a reduced EGR rather than a fully deactivated EGR,believing that all that the sensor requires is a heat source and so a hole (13mm dia) was drilled in the blanking plate which allows a very small amount of EGR to flow,but only enough to keep the sensor happy.

In over a thousand miles the car has been OK (barring DMF of course).

It occured to me that owners of DPF'd cars may also want to consider this mod.The reason for the DPFs is that for cars to have the correct amount of NOx reduction (EURO 4) the EGR has to put a greater amount of Exhaust gas into the inlet.This reduces the NOx further,but also increases soot particles,hence the need for the DPF.If you restrict the EGR you will not only have better engine performance and life,but you will also give your DPF an easier life as well.Also,should anything other than soot (which is reduced with this mod) be tested for the MOT in the future the plate (on the V6) takes only minutes to fit or remove.

no sensor for temp ..the ecu when opening the egr will see a flow rate drop from the air mass (less air being sucked in).also will know the egr is open / closed via its feed back from the solonid ... as you have done is the best way a blockage with a hole so the ecu still sees its air flow drop and is contented ....