The Check Engine Light can illuminate with codes due to the lack of EGR (exhaust gas recirculation) flow caused. This is commonly a result of a clogged passage in the intake manifold. To correct this problem, the EGR valve has to be removed and the passage cleaned thoroughly. Partial restriction of this passage can cause smog test failures for the NOx emissions without causing a drivability symptom.Google+
Car Problem Reports
Ford Contour Check Engine Light Due to Plugged EGR Passage
Ford Contour Problem
Exhaust & Emissions Affected: 2.5L V6
Average Mileage: 84,633 mi (60,000 mi - 108,900 mi)
Check engine light came on and needed to replace oxygen sensor and vacuum solenoid/EGR valve solenoid.
Visitor, 1997 Ford Contour, 85,000 mi
still going on.
codes 420 and 430 cleaned and replaced o2 and fine for awhile then it starts all over again.This is a constant problem and I am tired of.
Visitor, 1999 Ford Contour, 60,000 mi
have not repaired 3 months until inspection