Could someone explain exactly what the EGR does and what effects it will have to delete it, and how you would go about it. It isn't for my firebird, i am reading a code on my k5 blazer that says my egr is bad or throwing a code. It is a 305 tbi. If it will help me out, i will do away with it instead of buying a new one.

make it simple because i'm not very mechanically advanced.

Thanks
matt

 

Scrapping the EGR won't get you any extra power (contrary to popular belief) but it will make the engine more prone to detonation. All EGR does, is take a small amount of burnt exhaust gases, and recycle them back into the intake charge. These gases are inert and can't be burned again, so they serve to help cool the cumbustion chamber when they pass back through, which helps prevent detonation.

If you're set on removing it, you just pull it off the intake and make a plate to cover the holes. That's it. It'll keep on throwing the code forever though.

There's not much to go wrong in the EGR system. There's the EGR valve itself, the passages in the intake (which can get clogged wtih carbon over time,) and the vacuum solenoid or valve. In GM vehicles, the EGR valve itself is what tends to go out. They develop holes in the diaphragm. Get a small mirror so you can see the bottom side of the valve (inside the saucer looking section.) Crank the engine up, and take a vacuum line straight from the intake manifold or the bottom of the carb and hook it to the valve. You should see the diaphragm inside the valve move and the engine should die. If it doesn't move, replace the valve. If it moves and the engine runs fine, take the valve off and clean the passages. If the engine dies (or stumbles badly) replace the vacuum solenoid/switch and the vac. hoses that run to the EGR valve.

 

I'm not so sure I agree with that. If the gasses are inert and can not be burned the egr system would not have been put there in the first place. Gm isn't going to spend money on a system like that just to "cool the combustion temps, when they could have done the same thing by changing around timing and compression. I don't like it because it heats your intake manifold up, reducing the air density, looks ugly, and takes up space, not to mention the fact that it coats everything with a nice layer of carbon. It is true that the egr valve is closed at WOT, but it has no use beyond emmisions control. Make sure to delete it in your chip or else the computer may think it is still active and advance timing causing detonation.

 

TheGreatJ is actually right, the reason why it is an emmisions device is becuase it lowers the temperature of the combustion chamber (not actual cumbustion temp) which helps reduce NOx gases which are produced when the combustion temp reaches over 2200*. your right when you say GM wouldn't waste its money on something that just reduces cumbustion temps unless it also reduces emmissions, which it does.

 

I didn't plan on taking the egr off, I just wanted to diagnose the miss I was having. i figured it taking it off made it run better i would do it.

The truck seems to miss at low rpm under load, llike in od trying to accelerate. It threw a code of 32, which the friendly people at autozone told me was the egr valve. I took it off and cleaned it and it is still having the problem.

I don't know if it is the silinoid or what. Maybe it is an unrelated code all together. I'm not for sure. Would the egr cause this type of problem?

Thanks guys
Matt

 

It could cause that type of problem if it was sticking open, but if that were the case it would likely show other syptoms as well (i.e. rough idle, etc.) The EGR code is probably a false code, being caused by the bad O2 readings that the misfire is giving you.

I'd look into the ignition system for this one. Check the plugs, wires, cap, and rotor for corrosion, particularly the coil wire, and spray the wires lightly with soapy water while the engine is running. If the wires are breaking down, that'll show you where.

 

The EGR is an emissions device. It's primary function is to reduce your NOX, N2 or whatever it is emissions, it also helps slightly with hydrocarbons.
In order to delete the EGR you remove it and make a plate as has already been stated however you must then do some prom tuning to remove it as the motor will be looking for it and you will actually loose power in some situations.
Fix it or remove it properly.