check engine

Hey there. I just started getting a check engine light and the only code I'm pulling is code 41. This is a newer o2 sensor and I have a replacement but was wondering what else could be the issue. I bench tested the grey and black wires and received rising and lowering voltage when using a torch...

2004 ford range 2.3l dual cam first of all **** the 2.3l dual cam 4 engine, every bolt is in a ****ed up location this engine sucks to work on. But here is my problem i have no clue wtf is going on my old gasket was warped so it was leaking oil into my spark plugs(or that was my best guess)...

Anyone know how to retrieve the codes for the Check Engine light? 1990 B ll 2.9L Manual