[olddog]

Ronbo I'm no expert and just learning myself. I don't feel qualified to be telling anyone what to do, however I must pass this on to you. Everything I have read of EFI from many sources warns that locating the O2 sensor too far from the engine will cause problems. Even MassFlow tells you this in their instructions. Everyone seems to say it is better to put the O2 in a single tube than locate it too far away at the collector. I think 15" to 18" from the head is what I read the most. Mine is set up this way.

If you have not installed the headers and side pipe yet, I think it would be best to locate an O2 bung in a single tube at the recomended distance on each side. If you want to try it at the collector first, you can plug the other bungs. At least you would then have either option with the least amount of work.

I on the other hand, am thinking of adding a bung at the collector so I can put a wide band O2 in so that I can work on tuning the system. So I think the bung at the collector is a good thing to have. I just don't know that it is a good place for the O2 connected to the EEC.