Key in on things that will impact both banks. I had this same problem on my daughters 95 Mustang (3.8). I found a couple of vacuum leaks, but that didn't fix the problem. I noticed that the Baro reading was reading like we were at around 5,000 feet, but we are close to sea level. I cleaned the MAF and the Baro reading corrected itself. The codes have not been back!
These codes are telling you the computer has made as much adjustment as it can but the right side O2 sensor still isn't switching, this probably means the sensor is bad if there are no other codes. If you had codes indicating both banks were at adaptive limit then I would suspect a fuel pressure problem or blown FPR but that's not the case.
Hey glkearns we got the same problem same year what the hell I pulled my back tank and bad fuel pump and toss it behind the shed and rerouted the plumbing still a low pressure on the injectors so says the mechanic at the shop now I have to replace the other fuel pump it's always something let me know how you solve your problem.Thanks
Check your vacuum lines. My codes havn't been back. Now I am just waiting for all the self checks to get done to pass smog. I'm changing my t'stat out tomorrow (back to a 195 deg from 160 deg) apparantly it's not exiting warm up and the computer won't complete the self tests without...If that's not it, I start changing o2 sensors.