Hello.. I just got the above said Galant for a very good price granted it needs some work but the only thing that I can't seem to figure out is the egr system. It seems like you need a rocket scientist to figure it out. I went to autozone to read the check engine light and he said it was the code for the egr and of course sold me an egr valve. After removing the old one it seemed to work okay but I put in the new one anyway figuring what the heck.
Three days later the check engine light is still on. They said if the computer detects that there is no problems over time the light would go out. Just like it takes time for the error to be there before the light comes on. I disconnected the battery to reset everything. The car started and ran on the first go, no engine light. Restarted the car again and it had a hard time idling eventually it died in a few seconds, after restarting 3-4 times it eventually stayed running like before and the light came back on.
So after inspecting the vac hoses there seemed to be no vac at the egr valve at idol or revving the engine. The vac that goes to the egr comes from some round thingy (I guess I'll call it a check valve?) and also branches down to something else I assume is the DPF?. There was some vac at the round thingy, I removed it and attempted to blow and or suck through the inputs and it seems to work, didn't leak. The DFP? has another hose on top and a connector. If I remove the upper hose and plug the DPF? input the car tries to die.
After searching around I found a site that said you could tweak the computer by adding a resistor inside so the computer will go to federal standards (which will ignore the egr) instead of CA standards but I think it was for a mirage. Well I can't find the site again but didn't know if it would work for the galant anyway. I'd have to pull the computer and compare it to the pics. AND I don't know if the state inspection place would pick up on it.
If anyone has some kind of diagram of the egr system with component descriptions would be helpfull. Diagnostic help would be better.
I also found another area with someone else that had what seemed to be the same problem but after reading all the posts, at the end he gave up and sold the car.
I am good with mechanical and electrical stuff I have a meter and if needed I could dig out my 1964 tube type o-scope. But I need to know what to look for.
.... After searching for along time on the net and only coming up with BS AD pages (information super highway my butt!, AD highway more like it). I have found a few explainations on how the egr works, along with the dpf.
A lot of the stuff I found pertained to fords but the principal is basically the same. Another thing I don't understand, there's a component (small black cylinder) with bigger vac tubes (and electrical connector) that, at idol, makes a tick noise (kinda like a sticky lifter). When revved up it gets faster and almost makes a high piched noise. If I mess with it at all (remove hose(s) or connector) it makes the car run rough. So that must be working.
The only thing I mess with that does nothing is what I think is the DPF thingy. Two hoses in and electrical connector.
Please help. I can't imagine that no one knows how to fix this. I'll make pics and video if need be to troubleshoot. I only have a few days till I need to get an inspection.

 

dude, i will just be blunt with you. 2000 was the first year in galant for immobilizer. meaning computer chip in your key that has to be programmed to you pcm(computor). if you swap out that pcm without putting in a new immobilizer unit it will never crank. 2000 year model ONLY when you replace the pcm YOU HAVE TO ALSO REPLACE THE IMMOBILIZER ECU. will not crank otherwise. also you have to program the keys to the new pcm as well, or will not crank. now, the egr system in the 3.0l galant isnt very complicated. not enough time to explaint it all, but i will tell you this, the egr solenoids have been known to fail. also the vacume lines going to those same solenoids can clog up and cause a failure code. 8 times out of 10 when a car of that body style(1999-2003) comes in with an egr code the ports in the intake are clogged up. intake will have to be removed and totaly striped of throttlebody, and all sensors. you can send it to a machine shop and have them put it in a hot vat for a few hours. that works wonders and will unclog every port on the intake. or you can try cleaning it out yourself with chemicals or some kind or a flex hose you can put on a drill and manuver. the carbon is very hard to get out by yourself but can be done. be patient is all i can say.we only use the hot vat method because it will unclog those ports everytime. pick your poison dude!! good luck!

 

Well.. After searching around and a little help from local garage. I replaced the EGR solenoid, after all it's the next thing down the line.
What is this thing really? I disassembled the old one and it doesn't make much sense. It's just a coil around two vac inputs. Is the material inside the metal tube temp/electrical sensitive? When the egr electrical out-put activates does the solenoid restrict/contract or something?
After replacing the solenoid I started it a few times then the next day drove it a bit. Finally got to the inspection place and passed but on the way home the check engine light went on again. Granted I haven't had the code read again but I am sure it's the same problem.
From the first 1-3 starts with the new solenoid the vehicle acted the same way it did before with the old/original solenoid did after the computer was reset, it just took longer for some reason....
I guess from searching around I must assume that there's a problem with the intake.
But after talking to the previous owner and my experience driving the vehicle, they stated that engine mounts were replaced, and it sounds like the transmission mounts need to be replaced, there's a loud squeak noise when the engine is hot when you accelerate from a stop or go to reverse kinda like hot rubber against hot rubber under weight. But no clunking like a engine mount.
The only reason I bring this up is because the vehicle shifts (AT) kinda funny sometimes. But I wonder if the above could have caused a exhaust leak, that, for some reason could effect the EGR system.
Still don't understand why after replacing the solenoid it took so much longer to throw a code with the new one.