P0131 Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit Low Voltage am not sure where its located or even where to start if anyone knows the location and how to change it your help would be greatly appreciated.

 

If you have less than 80,000 miles, take it to the dealer and have them check it out. Those civics have a common problem of the exhaust manifold cracking, and causing O2 related check engine lights. For that car, new exhaust manifold = free if you have less than 80,000 miles, as the catalytic convertor is built in to it.

 

LX Civics have that problem, not EX. My guess is the O2 is taking a dump, or there is a problem in the wiring.

 

Oh, BTW the Primary O2, is on the exhaust manifold, near the head. Its the first O2, as the second is after the cat.

 

thanks for everyones help