QuestionHi Ted,
I have a 1997 Camry XLE (V6) with 140,000 miles on it that failed its smog test twice. Here are the results from the first test:
15 MPH,1747 RPM
HC = 25, MAX is 52 = Pass
CO = 0.01, MAX is 0.49 = Pass
NO = 967, MAX is 424 = FAIL
25 MPH,1736 RPM
HC = 18, MAX is 36 = Pass
CO = 0.01, MAX is 0.46 = Pass
NO = 1,115, MAX is 711 = FAIL
The test only smog technician said I either have a failed EGR valve or failed oxygen sensors. I took the car to a mechanic who plugged a diagnostic device into the dash. He said the EGR was dead but all the oxygen sensors were fine. He replaced the EGR valve and the car failed again. Here are the results of the second test:
15 MPH,1754 RPM
HC = 23, MAX is 52 = Pass
CO = 0.02, MAX is 0.49 = Pass
NO = 1,213, MAX is 424 = FAIL
25 MPH,1723 RPM
HC = 18, MAX is 36 = Pass
CO = 0.01, MAX is 0.46 = Pass
NO = 1,479, MAX is 711 = FAIL
Not only did it fail, the NO numbers got worse! I am not a mechanic. The person we used is a mechanic for the US Marines who I trust. He fixed a nagging oil leak for us in the past. I am praying this is something simple - like the unit is not connected properly. The car is being saved for my 15 year old daughter to learn on, It will barely be used - maybe 1,000 miles over the next year. Any help, suggestions would be appreciated.
P.S. I have tried contacting the Marine and have not heard back. He is normally responsive, so he may be out of town for the holiday.
Answer
egr mod
This not complicatedf, the nOX readings are too high because Either the EGR system is not working or the engine is running too hot, first make sure the engine remains at normal temperatur and does not overheat. The most common failure of the EGR system is not the EGR valve but the EGR modulator valve that is sitting on top of the egr valve and has three vacuum hoses on it and an exhaust pressure hose on the bottom, try replacing this valve and have it rechecked. There is a picture attached that shows the valve opened.
