I haven't figured out the tuning software. That's a little out of my league and fetching what I need has been a struggle. No shops or parts stores around me have an OBD1 scanner that gives live readings. I've been told on this thread and in person that it's probably a faulty sensor. So I replaced it. Same story.
I'm curious with how the exhaust could possibly throw the code. Lower exhaust temps from going from cast manifolds to a more flowing stainless? I have the sensor in the y-pipe collector because that was the stock location. I'm just now noticing that the bung is located just before the driver's side fully gets into the collector. The catless cat pipe I have also has a bung. Ive moved the sensor there hoping that could help with it reading 100% of the exhaust flow. The drivers side header also has a bung there. Would it be worth trying that point to get a hotter reading?
I don't know what else it could be. So far I've only been informed on the sensor itself, the harness, and now the exhaust. The sensor alters the fuel trim, but what if the trim is off from something else. Would the sensor then throw a code if it was running rich/lean? Sounds backwards to me.