I found a leak on the vacuum tree on the intake manifold by the throttle cable assembly. I fixed that and after 35 miles of driving it’s not throwing any codes. I will drive it a bit more, and if it stays off for another 50-100 miles, I will comment that this is closed. So far it seems to have been related to a leaky fuel cap which was throwing a P0432 low leak EVAP and once that was fixed, it changed to being a P0172 too rich code. After the purge valve and sealing the vacuum tree, that seems to be cured too.
I have not touched the fuel injectors at all.
I will wrap up this thread for posterity in the next day or two if the codes stay clear.
- This reply was modified 1 month ago by Don Bishop. Reason: clarity regarding the fuel injectors