Question about removing the EGR.

[hotmustang331]

Ok, as some of you know, we are building the headers for my car from scratch. We have 1 built fully (driver). But I dont want to tap the pipe just so I can run the stupid EGR into it and pump hot air down my motor.
My question is this.

Can I pass inspection W/O the egr? Will they know its not there and fail me, and say we get a sniffer test later, will I pass without the EGR (will put the stock cats inline...race pipe goes back after inspection)?

I know an engine light will come on if we pull it, but I can have Tim turn the EGR off.

So is there ANY way for emmesion people to know that my rear 02s are turned off and that my EGR is turned off? I heard somthing about them hooking up a tool and sending a test signal through and seeing if the readings change to make sure your stock equipment is working...is this true?

Thanks!

 

[trinity_gt]

EGR is there to reduce oxides of nitrogen (NOx) which can form at high cylinder pressures and temperatures, such as during cruise when the spark advance is maximized. EGR is not used at idle nor at WOT so it's not hurting your ultimate power output. Believe it or not, it also has the benefit of reducing the engine's tendency to show detonation...

A sniffer test might well fail on NOx without EGR. You might be able to temporarily pull out some timing at cruise to reduce temps and pressures enough to reduce NOx formation.

Without any EGR plumbing (i.e. stuff blocked off...) it's likely the PCM will catch it and light the MIL. I've never heard of emissions checks getting that involved (i.e. sending test signals throughout the system.) In some places, no codes is good enough. Others will sniff and/or do a complete visual inspection. How far they're going to look into your engine bay for all the EGR piping to be hooked up is anyone's guess.

 

[hotmustang331]

Hmm thanks for the info. We currectly have 0 emessions testing. no sniffer, no code check either. Just a normal inspection.

But Austin has adopted the check where they plug into your OBD2 and see if everything is ok.

Are you certain that hot air being taken from the header and put back down the motor can reduce the chance of detonation? And isnt that unmetered air/gas its putting back in there?

I also wonder if durring agressive part throttle where I may see a little boost, will it work opposite and allow boost to bypass the engine and go into the exhaust?

 

[Cantslowdown]

Not to take over your thread hot but with my tuner i have the egr turned off but the egr and everything is still on my car..So am i losing power doing this?

 

[trinity_gt]

Hmm thanks for the info. We currectly have 0 emessions testing. no sniffer, no code check either. Just a normal inspection.

But Austin has adopted the check where they plug into your OBD2 and see if everything is ok.

Are you certain that hot air being taken from the header and put back down the motor can reduce the chance of detonation?

"A DOZEN WAYS TO PREVENT DETONATION

...

2. Check for loss of EGR. The Exhaust Gas Recirculation (EGR) system is one of the engine's primary emission controls. Its purpose is to reduce oxides of nitrogen (NOX) pollution in the exhaust. It does this by "leaking" (recirculating) small amounts of exhaust into the intake manifold through the EGR valve. Though the gases are hot, they actually have a cooling effect on combustion temperatures by diluting the air/fuel mixture slightly. Lowering the combustion temperature reduces the formation of NOX as well as the octane requirements of the engine.
If the EGR valve is not opening, either because the valve itself is defective or because its vacuum supply is blocked (loose, plugged or misrouted vacuum hose connections, or a defective vacuum control valve or solenoid), the cooling effect is lost. The result will be higher combustion temperatures under load and an increased chance of detonation."

http://www.misterfixit.com/deton.htm

You can also read the section "EGR Effect on Emissions and Driveability" at:

http://www.autoshop101.com/forms/h61.pdf

And isnt that unmetered air/gas its putting back in there?

No, since the PCM is commanding the exact amount of EGR it expects to see, it's already aware of it. Also, the gas is inert so it doesn't affect the mixture at all, aside from diluting it.

I also wonder if durring agressive part throttle where I may see a little boost, will it work opposite and allow boost to bypass the engine and go into the exhaust?

Lots of cars are running boost with stock EGR systems and aren't seeing adverse effects.

 

[hotmustang331]

Gotcha, thanks for the info. We will see what we want to do. But it wont effect WOT, so thats good. if I leave it off, ill be sure to let Tim know so he can tune around it.