chasing down P1124 and P1126 culprit

[S50Sinner]

As part of the diagnosis process for my 1998 2.5 5MT LTFT lean codes, I unplugged my MAF and drove a cycle to see if it would run any better with the base map as a means to rule out a bad MAF. I did this at the recommendation of an old thread I found during my search for solutions.

The car struggled to idle and got awful fuel economy, which to me indicates that the MAF is not the culprit. At the end of the cycle, I had codes P0102, P0112, P1316, P1317, P1318 and P1319. The first 2 have to do wit the MAF itself, which was expected, but the remaining 4 were misfires. All of those codes were clearly caused by me unplugging the MAF, so I plugged it back in confident that it's not the source of my problem, as its absence only made it worse.

But now I'm wondering if the misfire codes could tell me anything more than that. Do they offer any conclusive evidence either way, or have I only ruled out the MAF? It would be nice if I could just go ahead and order parts, but I suspect I'll have to keep testing for vacuum leaks until I cave in and take it to a shop.