I'm running a VF30 with the suggested support mods.

This is the second installation. First time I'd get the inefficiency code only.

I took the mods off for warantee work and they sat around for about 4 months.

Put it all back on and now it spools up noticably slower and doesn't hit peak boost (18psi) till 4200rpm. According to the Turbo XS plots it should be sooner. And it doesn't hit as hard.

Can the unichip lose its mapping? If yes, am I running stock Map? I don't think the map should have an effect on spool time but if so will TurboXS check troubleshoot and remap or just give me a dyno print out?

CEL comes on during highway travel with and without cruise control at 75mph

I had that CEL on my second unichip install [on an upgrade - a different scenario than yours]. It was related to remapping the chip, and that all unichips are not equal. There is apparently a 'correction multiplier' that is used to adjust for the differences in output for each individual unichip. Mine was incorrect when it was reflashed. I sent it on back and it was fixed up.

At any rate, when that CEL comes on, you've exhausted your ECU's ability to richen the mixture. Since it is your second install of the exact same stuff, I'd take a look for vacuum leaks first.

If that is unfruitful, you may want to ship that Unichip back to have a look at the programming.

HTH,