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Q: Oxygen sensor problem

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I recently paid $80 for a check engine light inspection from one of your mechanics he basically told me what the technicians at auto zone told me which was that the problem is with the variable valve timing solenoid he checked my solenoids and said they were fine. He also recommended that i get a new cat converter too but he said i would still be able to pass a smog. So i go for a smog check today and i dont pass they tell me i need an oxygen sensor and they bring up my check engine light code. Could it be the oxygen sensor causing my check engine light to be on ?

My car has 106100 miles.
My car has an automatic transmission.

Hi There, Yes, your oxygen sensor (among many other things) will absolutely cause the check engine light to come on. The oxygen sensors which are part of your emissions system read exhaust gases to determine whether or not the appropriate amount of oxygen is present in the exhaust. Based upon this reading, this information is relayed to the car’s ECU which then makes a determination as to whether or not to add more or less fuel to the engine. When too much or too little oxygen is present, this will cause check engine light to come on. Too much oxygen may be present in the exhaust gas due to things like an exhaust leak, a vacuum leak, a faulty mass air flow sensor (causing a lean fuel condition) or faulty fuel injectors. Too little oxygen may be present in the exhaust gas may be caused by things like a clogged air filter, a failing mass air flow sensor (causing too much fuel to be introduced to the motor), bad fuel injectors or a clogged catalytic converter. When the O2 sensor is not working properly, this will cause false readings to be relayed to the computer causing inaccurate adjustments to be made to the intake and fuel system in your engine. I would suggest having an expert from Your Mechanic come to your home to diagnose your emissions system.

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