Purchased a 2005 CTS-V a couple days ago. Got a good deal on it because it has a couple issues that someone here might've dealt with. Its throwing codes for cam position sensor, throttle position sensor, lean bank 2, and MAF. Sometimes when I try to start it it doesn't start and backfires pretty good. When she starts she starts right up and no issues running. I suspect that maybe someone had some bolt-ons and a tune and took them off and now its messing with it. Total guess. It still has a CAI and cat delete. Any ideas of what the issues might be?