The suggestion was "Replace all of them" Plugs and Coils.

If you would like, Start with replacing the passenger side ones (Cyl 1-2-3-4) and see if other cylinders are now misfiring, as your codes are for front left and right (1&2). I would recomend doing all the coils as your mileage is over 100K? Consider it normal maintenance after 10+ years.

8-cylinder, V8 (US models):
M60, M62, – Twin cam (two cams for each bank), 4 valves per cylinder, produced from 1993 through mid-2000s (US)
N62, N63, – Twin cam (two cams for each bank), 4 valves per cylinder, produced from early 2000s to current
Cylinder numbering is 1 through 4 on passenger (right) side and 5 through 8 on driver (left) side. numbers 1 and 5 are at the front, 4 and 8 are at the rear.
Ignition firing order is 1-5-4-8-6-3-7-2 (except S65 = 1-5-4-8-7-2-6-3).
Bank-1 is the passenger side (cylinders 1 through 4), bank-2 is the driver side (cylinders 5 through 8).

There are many How to articles on plug and cild replacement listed under the X5 Article tab above. http://www.xoutpost.com/articles/x5/...-e53-4-4i.html

Videos: BMW DIY Video – Replacing Spark Plugs and Installing High-Performance Coils in BMW V8 N62, 545i, 750i, X5, etc. | Bavarian Autosport Blog

Note: Please correct me if my info and thinking are wrong here. It has been a LONG week at work and my brain is FRIED.

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2005 X5 4.8IS
The Blue ones are always FASTER....

Current Garage:
2005 X5 4.8is
2002 M5 TiSilver
2003 525iT
1998 528i
Former Garage Stable Highlights
2004 325XiT Sport
1973 De Tomaso Pantera, L Model
1970 Dodge Challenger T/A 4 sp Alpine White
1970 Dodge Challenger T/A 4 sp GoManGo Green
1971 Dart Sport, “Dart Light” package
1969 Road Runner 383
1968 Ply Barracuda 340S FB Sea-foam Green