i have a 97 accord lx. My check engine light came on about 2 weeks ago, so i brought it to auto zone to get them to run a check. I'm not sure what the code was, but the guy told me the code was something to do with the egr valve.....he said it could be clogged or just bad and that i would lose on gas mileage and also that my car would run rich. I searched on this forum and a couple of others and read that many people have problems with this and they try to replace the egr valve themselves, but the check engine light stays on after replacing the valve. Some have said the only fool proof solution is to bring the vehicle to the dealership and get them to replace it. Should I dare try and replace the valve myself just to end up with the same results as others? Or does anyone know the correct way?? I'm not sure of the exact location of the valve, so any help with that would also be appreciated. Just trying to find out the best solution for the cheapest price. I just had to replace my a/c compressor and other stuff with my a/c and dropped $850, but i know that this problem needs to be fixed. Thanks in advance....

 

well, the thing is that sometimes it isn't the EGR valve that's bad. There's a whole system that controls that EGR valve and then a whole set of passages and ports that could be clogged.

Check all vacuum hose for connetion and leaks first.

I would check for vacuum at the EGR valve vacuum hose after the engine is warmed up to normal operating temperature. At this point you shouldn have NO vacuum.

If you do have vacuum then you can disconnect the wires from the EGR control box (it's on the driver's side mounted towards the front fender. It's a black box). Now check for vacuum again. If the vacuum goes to 0, then your ECU maybe be the culprit. If the vacuum is present, and all the hoses seem ok, then it's probably the EGR control box.

Now if originally you had 0 vacuum, you can take a handheld vacuum pump and apply 8 in of Hg to the valve and see if the motor stalls out. If it doesn't and the EGR loses the vacuum, then you know it's the valve.

I've seen the ports on F22s get clogged up too, so it could be that too. If you look on top of your intake manifold, you'll see a rectangle box that sits above the runners. Those are the EGR ports. If pop that off you'll probably notice a lot of carbon build up and maybe even some clogged ports. Probably not the problem, but it's always good to clean something when you service it.

 

If you don't have a vacuum gauge, there is a diaphragm behind the EGR valve. Push the diaphragm in and if the car starts to stall out then the EGR valve itself is good. It might not be getting vacuum or something else.