[hewittca]

It sounds like you are hitting it in all the right places to try and diagnose the issue. With the knowledge that it was running great but has now developed this issue, that rules out that there is any real problem with the swap itself. I think looking into the O2 sensors is a good next step. I would also check that you have the correct fuel pressure if you can. Please keep us up to date and what you figure out. These types of threads are always very helpful for anyone who has similar issues in the future!