I am worried that I am having issues with both. My check engine light flashes more than I'd like it to but a very small amount. I've done the wires, plugs, and coil packs.

I've had the codes read and O2 fault codes pop up. My O2 sensors have been previously been changed prior to me owning the vehicle. I was given no history on the vehicle!

Can aftermarket parts such as an O2 sensor cause the rare flashing check engine light? The light is on all the time but flashes literally 15% of any drive and seems to be random when it does flash.

Help!

 

What are the codes?