What should I do if my engine failed a smog test?
Step 9 – On older engine’s an EGR valve is used to lower the production of Nox gases which are harmful to humans, if this valve stops functioning a smog test will fail. When a smog test is due its best to take the vehicle to the smog station after its been driven for a time to effectively warm the engine and exhaust system.
What can be done about high NOx in smog?
The solution to this problem is called De-Carbonizing. It usually costs around two labor hours at a smog check repair station. It will remove a good amount of carbon out of an engine. This will increase combustion space, lower compression and lower NOx. 5. Engine Overheating – Inadequate engine cooling can will high NOx.
What to do if your car fails the NOx test?
If you own a non-EGR equipped vehicle, and have failed the emissions test for high NOx, pay close attention to the Catalytic Converter. Read about Catalytic Converter
When does the EGR system cause high NOx?
The EGR system’s job is to re-route a small amount of exhaust gas back into the intake manifold to help reduce combustion chamber temperatures. As mentioned above NOx is created when combustion chamber temperatures reach above 2500F.
The solution to this problem is called De-Carbonizing. It usually costs around two labor hours at a smog check repair station. It will remove a good amount of carbon out of an engine. This will increase combustion space, lower compression and lower NOx. 5. Engine Overheating – Inadequate engine cooling can will high NOx.
What makes a Jeep Wrangler fail a smog test?
NOx was the last addition to the list of monitored exhaust gases. Misconceptions regarding the conditions that promote its formation still exist. I am working on a 1995 Jeep Wrangler with a 4.0L engine that has failed to pass a smog test due to high NOX.
If you own a non-EGR equipped vehicle, and have failed the emissions test for high NOx, pay close attention to the Catalytic Converter. Read about Catalytic Converter
The EGR system’s job is to re-route a small amount of exhaust gas back into the intake manifold to help reduce combustion chamber temperatures. As mentioned above NOx is created when combustion chamber temperatures reach above 2500F.