I had a low o2 issue for sometime and caused a ton of problems until I FINALLY corrected the problem. I blew a head gasket and the car had 10 miles on a fresh built motor. I elected not to take the motor out of the car after the oil became what looked like a chocolate milkshake. I was told that I could change the oil a couple of times and MAYBE things would be OK, WRONG!!!! The second time the car blew a head gasket it was found before the antifreeze got to the oil. I replaced the head gasket and said I was not going to drive the car until I found the low o2 issue. I cleaned EVERY electrical connection on the car and applied a liberal amount of dielectric grease to them, changed the injector harness (caspers), removed the factory ground connectors and crimped a single copper grounding connector to all the ground wires on passenger side head. Put everything back together and started the car and had 800 o2s for the first time. I drove the car to work a couple of days later thinking everything was ok until I launched the car about five times and noticed some knock which I should not have. The car was set at 15 psi with alky injection (should have absolutely 0 knock) at the boost level. So I popped the hood and thought I heard a little bottom end noise and decided to let my machine guy listen. He said it sounded like the bottom end was bad . I pulled the motor and it was KILLED. The rust in the block that dumped in the engine on the first blown head gasket is what got it. The block had to be bored .030 to clean it up. The crank was turned .040 just to clean it up (which cannot be used). My NEW engine is ready for pickup tomorrow. It has forged stroker crank, scat forged rods, forged JE pistons. Should be a blast after I get it back together.
I REALLY hope you get your o2s corrected before you have any serious issues.
Best of luck
