[SOLVED] Cylinder 1 Misfire - P0301 / P0300 Mystery

[Toothbrush]

Turned out to be incorrectly installed keepers on one of the exhaust valves (cylinder 1), causing an exhaust leak.

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Hi! Looking for help to track down a misfire on cylinder 1 for a 2007 e70 4.8i. Any help appreciated

P0301 - Cylinder 1 Misfire [0029CD]
P0300 - Random Misfire [0029CC]

Check Engine Light On
Rough Idle Cold & Warm
Some hesitation under load
All new Plugs
All new Coils
Cleaned Vanos sensors
Switched plugs and coils around (cylinder 1 & 2, 1 & 5), even tried old plug/coil in cylinder 1, no change in code
Changed coolant hoses (to fix a rotted fitting and associated leak)

Have replaced Valve Cover gaskets and all related sensor seals (vanos, eccentric shaft, upper timing cover, vacuum pump etc) during valve stem seal replacement
Have replaced worn crankcase vent pipe (was leaking)
Smoke tested (paint can/mineral oil from ebay) and see no leaks from intake or crankcase

I haven't had a compression test done yet, however, there was no misfire or roughness and no CEL (at least not like now) prior to all the work done above (all at the same time) even though it leaked oil/coolant and smoked like crazy.

I did have the engine partition off to make room and so I could replace all four major parts. The lower center piece was a pain.

I checked the voltage to cylinder 1 fuel injector and wiring and listened to it tick, all numbers matched specs and it sounded like it was operating correctly.

I'm wondering if water/moisture from rain during the 2 weeks I had the engine apart might be the cause. In ISTA - the Oxygen Sensor State for Bank 1 doesn't fluctuate at all (no mater the engine state) like bank 2 does. Fuses are good (30 amp under the footwell).

I'm new to INPA/ISTA but here I've attached an image of the value I'm talking about.