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
Mercury Cougar Check Engine Light Due to Plugged EGR Passage
Mercury Cougar Problem
Exhaust & Emissions Affected: 2.5L V6
Average Mileage: 118,000 mi (101,000 mi - 135,000 mi)
I just purchased this last Sunday.The engine light is on. I took it to Autozone and they said it was a egr code..There is also a bad smell of gas and excessive fuel consuption when over half a tank of gas.
Had system cleaned, but keeps coming on every other month. I've tried using engine cleaner additive when filling up with supreme gas clears it for a month then comes back again