Exhaust System EGR Delete Diesel

Discussion in '1st Generation (2004-2011)' started by kes, Tuesday 27th Oct, 2015.

  1. kes Club Member ★ ☆ ☆ ☆ ☆

    Hi everyone,
    I would like to delete my EGR if possible and was wondering if anyone else has done this. The EGR piping seems really complicated and unlike any other car I have had. I would like to block the piping as close to the turbo side as possible to save the gasses going along the extra piping.
    FR-V likes this.
  2. Ichiban Founder Staff Team

    England CJ Leeds
    EGR in diesel in principle and good to have to atomise the diesel fuel , the fact people say to delete them and you don't want this entering the intake is a bad move personally.
    kes likes this.
  3. Zebster Guest

    EGR reduces NOx emissions. As this pollutant is at the centre of the current VAG scandal, I'd expect future MoTs to include a check on this. Cars with disabled/deleted EGR would then fail a more thorough MOT.
    John Dickson, FirstHonda and kes like this.
  4. Bones126 Club Veteran ★ ★ ★ ★ ★

    England Dave Birmingham
    Hi Kes, when I had a my map done I inquired about this. Their opinion was for the gain you get it is not worth the money as you will have to remove the EGR and blank it off they said. You can not just turn off a bypass.
    kes likes this.
  5. Zebster Guest

    EGR delete remaps cannot completely close the valve, there will still be a 4.7% baseline flow... Hence the need to physically blank the valve IF you really want to completely stop the flow (but then you still need a remap to suppress the MIL that arises when the ECU realises that MAF isn't falling when EGR is requested).

    The standard map closes the valve at accelerator openings greater than 50%, so performance gains from blanking are minor, but you do minimise the build-up of crap in the intake tract.
    kes and Bones126 like this.
  6. ArcticFire Club Veteran ★ ★ ★ ★ ★

    Scotland Graham Scotland
    Would an EGR delete effect emissions come MOT time?
  7. Zebster Guest

    Yes, but currently there is no emission testing on diesel cars, merely a visible 'smoke test' when the accelerator pedal is floored.

    But - in the aftermath of the VAG scandal - surely an emission test must be on the agenda? As a bonus, this would also catch those diesel cars that have had either their EGR disabled or DPF removed!
    kes likes this.
  8. ArcticFire Club Veteran ★ ★ ★ ★ ★

    Scotland Graham Scotland
    I didn't realise that!
  9. jimjams Guest

    EGR reduces NOx because, by inserting exhaust gas back into the inlet, the amount of Oxygen is reduced.

    The main "problem" with diesel engines is their high NOx emissions (compared with petrol engines) which is due to the fact that they run very lean. Lean means a low amount of fuel compared with the Oxygen in the air, so by shoving exhaust gas back into the intake, the amount of Oxygen is reduced, which thereby makes the "burn" slightly "richer". (note that the exhaust gas is cooled before it goes back in, either in the turbo-inter-cooler or in a separate heat-exchanger).

    In a diesel engine, ironically, EGR also shoves particulates back into the engine, which increases wear, and over time this increases the amount of particulates, which further increases wear, which ...etc etc etc

    Even without that fact, of its own, running richer will cause an increase in diesel particulates, hence the introduction of the DPF into the exhaust (I can only assume that the exhaust take-off comes after the DPF in a car equipped with a DPF, but I might be wrong).

    But as mentioned, the regulations might eventually be tightened so that NOx is measured on an MOT, but by the time that happens I would think that most diesel cars with an EGR-delete (those without a DPF) will have reached the scrap-yard anyway (due to rust or other uneconomic repairs)
    kes likes this.
  10. kes Club Member ★ ☆ ☆ ☆ ☆

    Thanks for all the info everyone. Never realised some consequences of deleting the EGR.
    My EGR is already partially/fully/95% closed due to a remap. I was looking to blank the pipes that feed to the EGR from exhaust and return to inlet from EGR. My reasoning is to stop exhaust gases and fresh being routed to an area which is now closed. The difference it makes is small but might help things move along more quickly. The inlet side looks easy to blank and is just the generic plate as found on eBay. However the exhaust side looks very different. There was someone on civinfo selling these types of plates but he no longer does. I will try to upload a picture to show what I mean.
  11. Zebster Guest

    You mean HUB... he was massively over-selling the benefits of those plates!