Bad o2 sensor ???

First of all sorry for the bad English, i am from montreal quebec , canada and i speak french !
I have a 2005 mustang GT. It’s a little street strip car that i have build by myself over the years.

60 lbs FRPP injectors, Procharger supercharger, camshaft, water methanol injection, ford racing performance intake manifold and few other stuff that are not engine related.

I did blew the engine in june. A connecting rod had enough after a few 11.1 pass at the dragstrip. I did tune the car my self. No sign of detonation. Simply too much power for the stock rods.

So from there i did rebuild a new engine with stronger parts.

Timing is good, i did a leak down test wich was good, compression test was perfect and also a vacuum leak test with a real smoke machine from OTC just to be sure. Turned out i had a small leak near the intake from a hose that didn’t had a clamp on it, wich i fixed.

Here is my issue :

The car won’t run good and is very difficult to start. It got flooded on BANK 2. I have managed to do a datalog with my SCT handheld programmer after a really difficult cold start ( i had to floor it to go in flooded mode) . I saw an o2 sensor on bank 2, that would not move at all. On my handheld the STFT would go below 1.0 if the sensor detect a lean condition, and above 1.0 for a rich condition. The sensor on bank 1 was reading fine from .94 to .99. The one on bank 2 was reading 0.60 and would not fluctuate.

My questions :

-Can oil from the engine blowing up could contaminate the sensor to the point it would not read at all ?

-Can an o2 sensor be reading extreme lean and ask so much fuel to the PCM that it would flood bank 2 since my injectors are way bigger than OEM ones ( yes the tune has been made for those injectors) ?

-can a o2 sensor give my that much of an issue with the car ?

I do have power to all 8 injectors and all 8 coils. I do have 12v to the o2 sensors.

If you could give me a clue or if you have any idea of any kind i would really appreciate.

Thank you

Alex.

I would say its very possible, I ran into a similar issue with one of my cars.

I did an engine swap in my 03 Marauder which has longtube headers installed. When I would run the car for a while and it got up to temp (and out of the cold start loop), bank 1 would flood like crazy, the car would start popping and barely stay running. If you tried to drive it, it'd often stall out.

It turned out the bank 1 secondary O2 wire was laying on the header, and as the car would warm up it would heat up the wire and change the resistance values in the O2 wires that the PCM was reading, making the PCM think the car was running lean. The car would then start flooding the engine on bank 1. When I zip tied the wire out of the way, all was fine. I will also say while this issue was going on, the car never threw a check engine light.

I would at least check your sensors, but if you sent oil down the exhaust I would suggest replacing all of those sensors. OEM or NTK is what you want to stick with, NTK is the manufacturer for Ford.