keep failing NOX new spark plugs and oil change and NOX went higher on 2002 Dodge Stratus

also new thermostat

Asked by for the 2002 Dodge Stratus
2 answers
do u have eng codes? nox is from high temp in combustion chamber. timing,egr or catt issues
You need to put the same spark plugs that were from initial build. Champion any other will cause problems.