My 99 Outback Sport just turned over 80,000 miles a couple of weeks ago and right about that time, a CEL came on. Autozone diagnosed it, and it read, "2 codes"...P1130...definition: front 02 sensor (AF) circuit malfunction (open circuit). Probable cause: 1. open or short circuit condition. 2. Poor electrical connection. 3. Failed O2 sensor."

 

My question is, why would it say "2 Codes", yet no other code number or diagnosis come up? I figure it is most likely the front 02 sensor, as right around the same time as the CEL, I started hearing what sounds like an exhaust leak or rusty pipe in the same area. Anyone else ever experience this? Thanks for any help.

I just replaced the front O2 sensor, in my 99 OBW last week. Sensor cost $61 from e-bay. Does your car run poorly from the bad oxygen sensor?

 

Don't know the answer to your 2 codes question.

 

Muffler rattly buzzy noise most likely from loose shrouding around the exhaust pipes.

The car runs very good. The gas mileage is not the best, but it is hard for me to determine how good the mileage is as I have only had the car back on the road for a bit more than a month.