Q: 1999 toyota corolla smog fail due to high emissions

asked by on May 16, 2017

The car failed smog test in California for - OBD system checks, high emissions for HC and CO. I plan to sell the car and hence I want to do minimal repair to get it to work. The diagnosis done so far are the following: - valve cover gasket is loose and hence oil has drenched the O2 sensor and spark plugs and wires. The estimate is 900$ for changing the O2 sensor, valve cover gasket and the spark plugs and wires. Can you please suggest the minimal repair be done so as to pass smog without increasing the cost too much? I am ready to repair it myself with some guidance.

Thanks Sachi

My car has 185000 miles.
My car has an automatic transmission.

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Hi there. High emissions for HC and CO can be caused by more than 12 individual emissions sensors or fuel systems, ranging from your O2 sensors, catalytic converter, EGR Valve and more. As such, giving you the right repair advice would be very irresponsible of us without completing a check engine light inspection to download the specific OBD-II trouble codes and inspect the vehicle at your location.

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