Great! Good job figuring this out and thanks for letting us know.

Boost gauge is good and confirmed by electronic vacuum gauge and obd scan tool.  25/26 inhg at idle.  After much head scratching and digging over the weekend I determined that the boost solenoid and purge solenoid wires were switched.  The intake had been removed and nothing was installed correctly.  Surprisingly the two connectors are exactly the same, they are not uniquely tabbed to prevent incorrect connection.  After sorting everything out, clearing codes and resetting all service notifications I have a great running Mini!

Does the boost gauge show a vacuum at idle? I'm wondering if the boost gauge is reliable...

Looking for suggestions. Have read a pile of posts and still puzzled. Backstory: Just purchased car this week. 2008 MCS with 73k, super clean, few mods; Alta valve and Alta manifold adapter, CAI. Test drove car last week with CEL on but ran fine. Good boost, per standards started around 1800rpm and built from there. No issues. Seller had appointment to take in to check codes, which he did, prior to me purchasing. Codes came back as P0300-P0304 misfires. They recommended injector clean, blah, blah. My guess was HPFP. Anyway, struck a deal and bought car as-is for a good price. Picked up car and drove 20 miles or so and stopped for food (150 mile drive home). I think it was running correctly and was building boost at that point but I can’t honestly remember. I did drive it for a short time in Sport mode. After 20 minute stop to eat I dumped in a bottle of fuel injector cleaner/carbon deposit remover, fired up, pulled out and in 30 seconds the Safe mode warning displayed on tachometer display. It was definitely in low power mode but had to get it home so drove the 120 miles home. Dropped it off to get it detailed when I got home so didn’t dive into diagnostics right away. Picked up from detail shop and drove home, CEL on but not safe mode indicator, but still in low power mode. Car has boost gauge and I could see no boost at all under any throttle conditions. Got it home and scanned with my BluePoint scan tool and got same P0300 codes. I’m not sure if the shop that looked at it actually cleared the codes or if they came back right away. I cleared codes, and disconnected battery for 30 minutes. Car starts and runs fine but builds no boost whatsoever. I checked all vacuum lines and see no issues. Manually applied vacuum to wastegate and it appears to be functioning. No CEL is currently on. Is it somehow still in limp mode with no CEL or MIL? Can’t believe it’s major as it ran great during test drive. I just can’t recall if it was ok before the limp mode light came on. I think it was but..... Any thoughts or suggestions would be welcomed. I am extremely mechanical so I’m comfortable digging into this I’m just stumped at why it totally lost boost with no apparent reason. Turbo shaft has a fuzz of play but I can’t believe that would cause a zero boost problem.