Post Injection

[petestoy]

I just recieved my EFI Live and just starting to play with it and have some questions regarding the post injection.


What does post injection actually do?
Is it strictly emmisions?
How much fuel is actually injected and how badly does it hurt fuel economy.

I read somewhere that if you put 1 in Table B1021 it will eliminate the post injection? Does that mean you actually put 1 in every box of the table?

Thanks guys.

[GMPX]

Yes, post is used for emissions, it does not make more power as it happens after the 'bang'.
They use it to control the DPF temps, it certainly does not help MPG!
If your DPF is still in place then leave the post injestions alone.

Cheers,
Ross

[tinman22]

if the truck in question is the one in his sig its an LBZ and there is no DPF... turn it off and no worries. egts will be a little lower (that I noticed with mine). other than that, no lossed that I have noticed... I dont have my laptop handy with table numbers but I zeroed out the post injection tables and I believe the multipliers as well.

[petestoy]

Thanks Guys, and sorry the truck is a 2006 LBZ so I don't think I have a DPF. Are the Tables B9301 and B9302? Post injection # 1 is already at zero. Do we just type into the table and save?

[GMPX]

I missed that too, LBZ the post injections are non functional anyway, but it's all in the ECM anyway.

Cheers,
Ross

[tinman22]

are you saying that the post injections are non functional in that they dont do anything productive but the injections happen... or that they are just "dead" tables that dont affect anything because the injections dont happen?

[lucky1]

I believe they are also used to keep the temps higher for the cat.

[tinman22]

well I certainly dont need that function anymore lol

[KB3MMX]

Did you notice any MPG increase?

Thanks!


if the truck in question is the one in his sig its an LBZ and there is no DPF... turn it off and no worries. egts will be a little lower (that I noticed with mine). other than that, no lossed that I have noticed... I dont have my laptop handy with table numbers but I zeroed out the post injection tables and I believe the multipliers as well.

[tinman22]

nothing I really noticed. I want to believe that I gained a quarter to half mpg. but fluctuations tank to tank can easily be that much different unless you do the exact same driving day to day. and that I dont do

[petestoy]

Not sure if there is an increase in mileage, there is more smoke when you come on it, but EGTS are lower so that might help you when you are doing long hard pulls.