Running a single O2 sensor in my turbo down pipe for closed loop?

[cpolaris502]

I've been running my truck OLSD ever since it was tuned in June. My stock O2 sensors are bad so that was the reason for that. Back when I tried closed loop before (one sensor in crossover pipe-bank 1 and one sensor in down pipe-"bank2 ") since bank 2 is reading all 8 cylinders with my log manifold, it always read a little differently.

I want to just run a single sensor in my down pipe and have it control all the injectors. Is it as easy as modifying the Injector Bank Select table to have be all 1's for bank 2? Or do I have to do some custom wiring, or is what I want to do even possible?

[AnthonyRSS]

Tagged for answers. This is exactly how I have my O2s in my turbo setup with a wideband on the downpipe.

[DSteck]

For older stuff, I'm not sure. I know the transverse mounted V8 car setups only use one O2. You might try comparing with something like that.

[cpolaris502]

From what I've been able to find from searching google, it sounds like the PCM needs to see input from both O2s in order for it to be able to go into closed loop. It sounds like I need two installed either way. I wonder if I can just set the injector bank select to have all injectors on bank 2 so that only bank 2 O2 sensor is adjusting fueling and bank 1 is there as a dummy. I may have to do some experimenting...

[5FDP]

Does anyone make an extenstion harness??

I know when I installed headers on my grand prix the front o2 sensor wouldnt reach the bung anymore, so a company that made aftermarket parts for these cars had a harness that was 15in longer. Plug the harness into the old plug in, add the length of that plus the 10in o2 wires and you'll have 20-25in of extra wire to reach the other side of the truck.

[cpolaris502]

If I have to move both sensors to the down pipe and add a bung I'll just extend the factory harness.

I just put a brand new O2 sensor in the downpipe (bank 2). Going to run the stock one in bank one and turn off all DTCs, or lights and set the injector select table to all 1's for bank 2. Hopefully that will will enable it to go into closed loop and allow bank 2 sensor to adjust fueling for all cylinders.

Sound like a plan?

[cpolaris502]

I put a few miles on it now with the way it is above. Seems to be working but I can't really tell if it's controlling all injectors off of the one sensor. My wideband bounces nicely around 14.7 (92 octane for winter). I'll just keep it this way until I notice something odd, but for now it works.