1) I am having similar issues. Im guessing EGR valve could be on of a few possible solutions. The car (2002 Protege 5) has 96,0000 KM on it. This started roughly 4 weeks ago, every once and while I would drive the car and it would, during idle (stop lights or parked), run really rough and go low low idle, like almost stalling. If I gave it a quick rev to say 3500, the problem would go away and not come back until a few days later. Then it progressed to happening everytime I drove the car, but again if I reved it quick, the problem would go away and not come back till I drove the car next.
Then this weekend it started again and if I reved it, it didnt go away, took about 4-5 revs and then it finally disappeared.
Im going to check plugs and wires tonight, and if I have time take off the EGR valve and do a cleaning on it.
Does this sound like it could be the problem, or more likeley A coil issue?
2) This How To, says to reset the computer? How do I do that and can I without messing anything up?
3) I spoke with a Mazda dealership today and they said If I take off the EGR valve myself I void the 7 year warranty and cant get the replacement, he said you shouldnt mess with it... BS? They said they will diagnose for $105, and they can tell me the problem. If its the EGR valve its all covered under the 7 year warranty and they will throw in the new EGR free of charge. If its not, at least Ill know what the problem is and I can try fix it myself if its the Coils etc...
Then I spoke to another dealership and they said it shouldnt void the warranty.
They also said that if its the EGR valve you should be getting a CEL? I havnt had one yet at all...
What do you guys think?
Thanks!