Engine Mechanical problem
2000 Honda Civic 4 cyl Automatic 6,700 miles
Check engine light is on. AutoZone read codes PO136 & PO137. Both codes are for oxygen sensor 2 in bank 1. PO136 says a malfunction exists in electrical circuit for the sensor. PO137 says input voltage from sensor is too low for current operating conditions. AutoZone says oxygen sensor 1 is closest to the cylinder head before the catalytic converter, while oxygen sensors 2 & 3 are located further downstream and are typically mounted in or after the catalytic converter. It also says bank 1 identifies the location of cylinder while bank 2 identifies the cylinders on the opposite bank.
Because car is driven so seldom, I'm not concerned about poor gas mileage. Car is running fine so fuel mixture must not be lean. Dealer quoted $220 to replace sensor and said engine isn't being damaged as long as fuel mixture isn't lean. I don't want to spend money to replace sensor. Will there be any problems?
Yes, maybe not in the very near future as long as vehicle isn't driven much, but will eventually cause failure of the Catalytic Converter and can cause engine damage. The sensor being bad will cause rich and lean run times.
You could probably replace the sensors yourself and save at least half if not more. They are not that difficult to change.