I have an 03 lancer ls and it keeps throwing evap codes. Ive replaced all vacuum lines, EGR checks out, replaced vacuum control solenoid. I drive it for a day and then p0401 comes up. Is it the EGR soleniod but no p0403? is this common to fail? 120,000 miles, runs like a champ 34 mpg. Idle is slightly rough.

Would taking off the throttle body and cleaning it super good help? There are 2 vacuum lines on the TB that have tiny holes, do these easily get clogged when cleaning the TB. I clean it at least once a year, not removing it, just cleaning it w/ spray and rag. Getting ready to sell, needs to pass emisions.

Spark plugs + O2 are new, I keep this thing tip top.... please help.