Bought what I thought was a 2004 g35 6mt, turns out it was a 2004.5. The ecm was fried in it originally so I got a new ecm for it which was from a 2004 6mt. I installed this before I realized that I had wideband o2s and it was 2004.5. I can't find an ECU for a 2004.5 and I need to find a way to use the narrow band O2 sensors with the 2004.5 wiring harness. Any suggestions on where to go from here.

ECM are not based on year. Take the original one and get the model number off it, there are MANY different ECM's for the G35 platform and you need to get an exact matching part or it will not work.

eBay will almost definitely have the ECM.

Already tried. eBay does not have one that is the exact model number. I got the whole electronic assembly when I bought the 04 one. So the car runs and drives. Just idles like **** and uses a lot of fuel because it can't use the O2 signal.

Ok then grab a copy of the FSM from:

https://www.nicoclub.com/archives/in...e-manuals.html

And compare wire colors for the O2 sensor harness, salvage another harness from a donor vehicle and splice it to the correct wires. EC - Engine Controls and PG - Power and Grounding sections should have everything you need.

Thanks you're a life saver

If you have the old ECU I can rebuild it so you don't have to go through all of that trouble. Just PM me if you need more info.