What is a egr valve and where located on a 1991 park ave?

Answer 1

EGR = Exhaust Gas Recycling. When running at less than full power, a percentage of exhaust gas is put back through the intake so that there isn't too much oxygen in the mix. Computer controlled engines can run far more lean than did their carburated counter-parts, thereby saving you and me a whole lot of fuel. But if the engine runs lean, too much oxygen can cause the combustion process to get EXTREMELY hot resulting in burned exhaust valves and possibly even pistons. Welcome to the world of the EGR valve. By controlling the amount of exhaust gas the computer is actually controlling the amount of oxygen, making the engine run far more lean and making valves last many times longer. If your EGR valve goes bad there are a couple things that can happen to your engine, one is bad the next is worse. If you're getting too much exhaust gas, the engine will run bad. If you're not getting enough exaust gas the engine will either run too hot or waste too much fuel. EGR valves on most GM vehicles are mounted on top of the intake manifold. They aren't usually too difficult to change, but many cars have a lot of "shroud" around the engine, to make it look "pretty". Sometimes that stuff gets to be a pain to remove. Whatever it takes, if the EGR valve is messed up, replace it at your earliest convenience. It will save fuel and possibly the engine.