My service engine light came on. Took it in to get the codes pulled. Got two codes, one for Bank 1 sensor 2 (O2) and 2 for misfire in cylinder 1. Since the sensor and cylinder 1 are on the same side of the engine, obviously I have either a bad coil, or bad O2 sensor.

THings to think about are if I had a bad O2 sensor, I wouldn't just have 1 cylinder misfiring, I would have all of them on that side randomly misfiring. But since I always see cylinder 1 along with the O2 code, this would lead me to believe the coil is bad.

I don't want to assume and replace things blindly here, so can someone tell me if I am on the right track here? If the O2 sensor was bad, I would have problems with all the cylinders on that side of the engine since the fuel to air mixture would be getting screwed up across the board on that side? Second, is cylinder 1 on the passenger side?

Since the coil may not be firing the cylider correctly, this would cause my O2 sensor to get a too rich, or too lean reading. I took the O2 sensor out and tested it with a propane torch and it seems to be good to me. It's fast to respond, and the voltages look good.

What do you guys think. Am I thinking too much here?