Thanks for the idea Matt. So what I did this morning was return it back to stock tune. I rechecked the fuel pressure with the vehicle running this time and got 59 psi. The previous reading was with the ignition set to run. I have taken it for a couple test runs, interstate and country roads varying speeds from 45 up to 80. No codes have reappeared and I'm getting a lot better gas milage. Before with the tune installed I average 11 and 12 mpg, with stock tune it jumped up to 15 and 16 mpg. Only time will tell though. The plugs I removed were the worst I've ever seen, they have only been installed for about 30,000 miles. I'm wondering if running the 91 performance tune caused all my plugs to foul. If anything changes, I will keep everyone informed. Thanks for the help.