[HEW]

So I recently purchased an 03 Lancer ES w/ 197,xxx miles and it ran fine during the test drive but on the drive home it started running pretty rough. So when doing my research to figure out what the issue(s) was I read somewhere it was probably the Mass Air Flow Sensor, so I ordered a new one and replaced it, no help. So I read somewhere that it's probably the Idle Air Control Valve, so again, I ordered/replaced, still no help. So now I'm here, figured someone on here has possibly encountered this same issue.

and there are no lights on the dash

 

[LancerSportWagon]

Can you add more detail on the rough running
Loss of power ?
High idle speed ?
Misfire ?
Will not pull high revs in a low gear ?


Air leaks will upset the running, if you have a split hose or loose hose clamp the idle will be rough.
Check the crank case breather hose, these can degrade as they get oil mist passing through.