Problem Reports

Cadillac DeVille

Report: Smog Check Failure Due to Excessive Carbon Buildup

Cadillac DeVille Problem

7 Reports

Me Too

Model Years Affected: 1991, 1992, 1993, 1994, 1995

Average Mileage: 135,500 mi (113,000 mi - 158,000 mi)

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.

Add to My Checklist

Find a Shop

Follow this Problem Report Unfollow this Problem Report

Visitor, 1994 Cadillac DeVille, 158,000 mi

Caddy failed due to NOx being too high on both high and low speed tests

Flag This

Like0
caddymike, 1993 Cadillac DeVille, 113,000 mi

Rookie
Car failed for high nox

Flag This

Like0
Visitor, 1994 Cadillac DeVille, 158,000 mi

Caddy failed due to NOx being too high on both high and low speed tests

Flag This

Like0
caddymike, 1993 Cadillac DeVille, 113,000 mi

Rookie
Car failed for high nox

Flag This

Like0

Related Items:

Check coolant level light
Check coolant level light comes on almost as soon as the car is started. The level has been ch...
Q&A > Cadillac > 2000 Cadillac DeVille
check gas cap light reset
check gas cap light will not go out
Q&A > Cadillac > 2000 Cadillac DeVille
car is running to lean will not pass smog.
car is running to lean willnot pass smog. I changed the cat converter,egr vaulve,two o2 sensors,muffler and vaccume h...
Q&A > Cadillac > 1995 Cadillac DeVille
Check Engine Light due to EGR control solenoid/valve failure
The EGR control solenoid or EGR valve may fail causing the Check Engine Light to illuminate.
Common Problems > Cadillac DeVille
Check Engine Light on Due to Faulty Catalytic Conveter
Failure of the catalytic converter can result in illumination of the Check Engine Light.
Common Problems > Cadillac DeVille