Another sr20 won't start topic

[wezurii]

Hate to be that guy but I searched and offcourse I have a different situation/problem, long story short

Car and specs
89 240sx coupe (base was auto ka24e)
blacktop s13 sr20, manual sr20 box

Car started with the old harness, didn't run right but instead of replacing stuff one by one like I should, I started doing all sorts of replacement and now it won't start at all

Installed new WS harness (still has old trans harness)
New starter (Tested it beside the car and works)
Installed a big O2 sensor as that should be the one according to all the info I could find(this was probably the problem as it was held by 1 of 3 wires
Fuel pump primes
Ignition barrel shows 12V
New relays didn't change anything
Clutch relay (checked and replaced but didn't do anything)

Now I am kinda running out of stuff to try
I still need to check
Old engine harness
Measure ECU Voltage

But besides that does any one you had a similar problem and what was the fix or any suggestions ?

Thanks in advance