What does the EGR setup on an 89 do? I am getting new headers put on my car and taking off the air pump setup and pre cats, but I also want to get rid of the EGR stuff as well. If I block off the tube and leave the sensor, will that log any error codes. I have been told that the sensor is just a temp sensor, so if I leave it in place or modify the setup it should be OK.
Any help would be appreciated

 

Exhaust Gas Recirculation

The EGR system reintroduces exhaust gases at part throttle into your intake manifold to burn off more vapors that did not fully combust the 1st time through the cylinders. It also cools cylinder temperatures down.

 

How would exhaust gases cool cylinders?

 

By the time the gases have gotten into the manifolds or headers and back into the intake manifold it is cooler than the combustion temps.

 

Scorps right on...believe it or not,the EGR is helping to cool cylinder temps when activated.Without it,your engine can ping,which is why many people who have stuck or bad EGR's notice a stumble and pinging in the engine.
The EGR,while an emissions device,is said to reduce cylinder temps as much as 500 degrees.

Thats not to say you cant delete it.However,Ive learned that you sometimes can benefit from another camshaft that can help bleed off excess cylinder pressure to help in reducing the pinging problems.Im not 100% sure so if someone knows better,to post here.But I heard this is true on say the LT4,which doesnt use an external EGR,and its due to its camshaft design.I have heard of many L98 owners who have disabled their EGR with no ill effects or also had a prom to turn off the EGR function.

The EGR switch itself just mounts onto the pipe and the switch hole is a dead end,in which you can remove the flexible pipe,block off the EGR feed hole in the pipe and leave the remained of the pipe bolted to the intake for the EGR heat sensing switch to remain active.But not sure if it will take some time before the intake warms up that switch to send a signal its hot enough simulating an egr function.

You may have to TEST your set up and see if the engine suffers any Ill effects from having the EGR itself and feed tube disconnected after headers are installed.
As long as the switch on the intake can get warm and not throw a 32 and the engine runs fine,then youll know.Personally,Ive left EGR on since it works fine and have no trouble with it.If you have emissions where you live,youll need to leave it alone.
:)

 

Don't have that problem, although I don't want the engine to be a real dirty engine. I have had a bit of a read about it and it appears that the EGR and AIR pump mainly work on warm up and don't do much when the engine goes to closed loop. My engine warms up pretty quick so it may be OK to disconnect it all.

 

They work in closed loop, but not at full throttle.

 

Scorps right, but for the wrong reason. It not cooler exhaust gases being introduced into the combustion chambers making it run cooler, its because the exhaust gases have no oxygen or much less oxygen content and that effects the combustion by causing less of a burn in the chamber.

Leaving the sensor hooked up to the EGR and not to the exhaust will throw a code. It requires the heat from the exhaust gases passing through it to signal the EGR is working. Simply conected to the intake will not generate enough heat.

 

They call these gases inert, and this is the main purpose of the egr system, to reduce oxides of nitrogen, this reduction comes from lowering combustion chamber temps. Many cars can run without the egr system, as long as the vehicle isn't running too lean, with no ill effects, (pinging)

 

So if I relocate the sensor to the headers, will this fix it. I am inclined to leave it on but just want to know what options I have.
I am going for a cruise with the Vette club on Sunday and one of the guys going has headers without the AIR pump. I will have to check his out and see if he kept the EGR pipe and how it goes if it is disconected