Levi likes si

My cel came on in my canadian 1999 honda civic si and when I scanned it was Giving me primary o2 sensor high voltage how do you fix this as it is annoying me the engine is a d16y8.

got2run5

High voltage means you're running rich which will ruin your cat.

Levi likes si

What should I do to fix this
Would badly fouled spark plugs cause this

got2run5

I'm not sure what mods you have and I'm not the most knowledgeable about engines but my recommendation would be to replace the upstream 02 and see if that fixes it.

Levi likes si

I replaced the up stream o2 sensor but I am still getting the same code I erased it but it came back same as before

ezone

Figure out WHY the computer doesn't like what it sees. I might monitor the actual output voltage of the sensor, and watch the values of that sensor in the datastream on a scantool. Then make decisions based on what I find there.