Smog Check Failure Due to Excessive Carbon Buildupon Cadillac Fleetwood

Excessive carbon build up in the engine combustion chambers may be the cause of a smog check failure due to excess NOx emissions. A "top engine" decoarbonization cleaning procedure will commonly correct this concern.

RepairPal Verified
Average mileage : 84,000 (84,000–84,000)
4 Years Affected: 1990, 1991, 1992, 1993
6 people reported this problem
0 people shared problem details
Related Items:
Everything passed except failed smog no's too high
The EGR valve or control solenoid may fail causing the check engine (SES) light to illuminate.
hi,i have a 90 cadillac brougham with a 5.7 liter and i think i have a vaccumm problem,i checke...

Related Content