Loss of power in low rpms, smokes when cold, loss of vac.

Hey guys. I have a 1998 civic hatchback with a dsm 16g evo3 turbo. I bought it 3000 miles ago. It was chipped and tuned by English racing in Camas Washington. Recently I went on a 440 mile trip that went from sea level to 5,000 feet elevation. When I started the trip the car idled at 30 vac and ran perfectly. When I arrived the car idled at 20 vac but nothing else changed so I thought it would go back up when I came back down. When I got back to sea level the car had only gone back to 22 vac. I let the car sit overnight and the next morning it had gone back to 25 Vac. Then something extremely strange happened. I was driving and the boost was about 1 psi and I was at around 3500 rpms when the rpms suddenly jumped to 3800 rpms. Then the check engine light turned on. I decided I would bring it to the mechanics the next day. When I started the car the morning the check engine light was gone. I took it to the mechanics and had him check the check engine light with the scanner. No problems came up so I decided to keep driving it and see if it changed at all. I'm not sure but it seems that since then it has started smoking more and using more oil. I'm not 100% sure about that because I've only had the car for a month. Today I drove 100 miles and it seemed that the car had actually lost power when the car isn't boosting. When the car was in vac it just didn't have the same torque as it did before when I first bought the car. Currently it is idling at 25 vac. Could this be a bad coil pack and one cylinder isn't firing? Or a bad turbo seal? I'm kinda stumped here and I would like to know if anyone else has had this problem before having the mechanic take the engine apart looking for the problem. The car has 93000 miles, new injectors, headgasket, and block. The air fuel ratio is about 14-15 idling and 10-11 under boost. Any ideas?

Vac leak?