Keep failing smog check due to high nox levels. Replaced pcv valve, o2 sensor, catalytic converter.
Wednesday, August 20th, 2008 AT 4:37 PM
1 Reply
2CARPRO JACK
MECHANIC
11,533 POSTS
Nox is exhaust temp which is controlled by the EGR valve. If the valve is vacuum operated, use a pump to open the EGR valve, the engine should stumble hard if not die, if it doesnt, the passages could be plugged. If the valve is electric, you will need the proper scan tool to make the valve open to see if the passages are clear or if the valve is bad