Hey! New guy here. Have had the 2003 Protege 5 for a year and a half and now the code comes up for the EGR valve and it is rough to start some times and rough at idle some times and at stop lights. So think I found it(not sure) Behind the engine next to the fire wall near center, but any one have a clue how to change it? I can't find a book on the model line any where. Is it tuff for a newbie mechanic to do or should I have a pro do it? Found the part at parts store for $125. Any help and hints would be greatly appreciated!
Mike

 

P0401 is EGR related, but doesn't necessarily means it's bad. It just means the system isn't working correctly. The EGR system consists of the valve itself, boost sensor, a solenoid valve and a pipe from the EGR to the exhaust mani. The problem could be one of the other parts is malfunctioning. If you're idling rough, I'd suspect your EGR is slightly sticking open letting too much air in to the mix (P0402 behavior as well) Remove the EGR valve and just clean it out as it gets full of deposits that can interfere with the valves ability to seat properly. I use Gum Out carb cleaner spray cans. Clean out the EGR, the EGR pipe and inspect the mounting point of the EGR to the intake. It can get some deposit buildup there as well. Be careful with the gasket. You might want to buy the gasket to have on hand in case the old one is bad or gets damaged.
If you're standing in front of the engine, the EGR is on the right side of the intake mani, which is most of the way towards the rear.

 

Thanks for the reply. I will try it. Hope I don't screw things up!