I think in a way you may have answered your own questions..sort of haha..You need to get your datalogger connected, and get a long pull on the highway at WOT at your full boost(7 psi?). You are right on for 1550 max EGT on a long pull, in 4th at WOT... .96 should be around where you want to be for 7 psi. That really is not rich. .90 is way too lean, and .94 would be a very minimum to run. I know i get almost 1 volt at wot in lower gears at 13 psi. Some would say that mega rich, but its not. The higer the boost, the more fuel you need, and once you start going over 10+ psi, you need to peg your o2 volts. But at 7 psi, you get a bit more room to run a little less fuel. If you got a CEL for too rich, that means that you pegged your STFT and LTFT at -25%, which means you have too high of idle fuel pressure. I run around 21-22 psi at idle, and its great, fuel trims look very good. I run the largest disk in the SFMU also, with about 1-2 turns open on the bleed valve, but thats for 13psi. YOu will prob need between 80-90 psi of fuel at 7 psi boost on the 310's. Oh, and that air filter you put on, prob is not really doing much of anything over your older one, unless it was super restrictive for some reason..It won't really make that big of difference, at least not enough to change your A/F ratio.