Well, I had this code, and I ended up changing the EGR solenoids to my car. Now, I know a few of you have had this code but I need to warn you guys. I changed my solenoids and all my vaccuum hoses, but the issue still remained. I suggest to ANY of you guys to check your COIL packs if you're having any acceleration issues. Believe it or not, my car did not run up any misfire issues but this ended up being my issue. The only way I figured it out was because my friend has a lancer as well and we switched the coil pack in his car and it ended up being that.

This all sounds dumb, but just keep an eye out guys, and keep your cars runnin

 

I too have a Lancer throwing P0403 every other start. If I clear it it will come back in 2 or 3 starts.

I have removed the EGR, cleaned and everything seems to functions normally. I have cleaned and cleared all hoses and everything seems fine there as well.

Has the P0403 error returned since you replaced the coils? I'm assuming you are referring to the ignition coils that are located on top of the engine that "touch" the spark plugs.

http://www.autopartswarehouse.com/sk...ings+Clearance