[Blxk.M235i]

Hey, so recently I’ve done my exhaust on my car. I did a muffler and resonator delete. The car sounds insane( waaay tooo loud) I have on problem tho. Normally u aren’t supposed to get a CEL after deleting those 2 but I did. I removed the cel With bimmer link but it keeps getting back after a few days. I would like to ask if someone knows how the OPF looks like and where it’s located? Because I’m getting OPF failure reading. I suspect that my car doesn’t have a resonator and the second thing I deleted was the opf but why weren’t there any sensors connected to it?