Cadillac Seville STS Problem Report

Cadillac Seville STS Smog Check Failure Due to Excessive Carbon Buildup

(2 reports)

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.

Related Items:
The torque converter clutch (TTC) may stop working due to an internal transmission failure. The...
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/...
My STS ( 180000 miles) is overheating in traffic after driving on the highway with AC on high....
my low beam head lights don't work but the highbeam lights do. Also my tail lights do work but...