I checked the search but I didn't find my answer. I got an SES light last night. Codes this morning were 32. Is the EGR system the rails with a metal tubes running to each exhaust manifold port? There is a 2 1/2 inch ior so canister on each rail, one rail on each exhaust manifold. These lead through hoses to a box on the passenger side. The only mods to my 92RS are an open element air filter. It's been on for 4 months and I've gotten no codes until now. I would have expected a related problem well before this.

 

The EGR is that little UFO shaped diaphram thats on the passenger side of the manifold, just under the throttle body. The valve usually gets carbon buildup and throws codes. A lot of times it will throw a code in the middle of driving, then when you start the car up after turning it off it goes away. Its not a scary thing, so you can replace it easily. What EGR does is recycles exhaust gas through the motor to reduce pollution.

The system with the tubes comming off the exhaust is the infamous A.I.R. system. On most members here, its usually the first thing to be ditched off our cars. It works for about 15 seconds when you start your car up for the first time each day, then it never gets used again.
Its purpose for that 15 seconds: To shoot air into the catalytic converter so it warms up faster thus begins reducing pollution. Its another GM novelty.

 

Not true. It injects air into the manifolds until the ECM goes into closed-loop, then sends air to the cat. It was in use before catalytic converters were, on more than GM cars.

FWIW, a lot of GM front wheel drive cars did not have A.I.R. injection. They were clean enough with fuel injection not to need it.

The EGR injects a small amount of exhaust into the intake charge under certain conditions to reduce combustion temperature, which in turn reduces the formation of nitrogen oxide compounds.

 

where is the evap canister then? is it the canister on the end of the A.I.R tubes. what does it look like?

 

on a camaro its next to your radiator on the drivers side its the black canister

 

ok thanks, but were is the purge valve on a carbed 305?