These two codes allow you to go to any level,cutscene,and area instantly.
cutscene modifier: press R to warp
D0281251 0010
8037E8F5 00xx cutscene select,change only this
D0281251 0010
8037E8F6 00AA-do not mess with
D0281251 0010
80381FDB 0000
D0281251 0010
8037E8F4 0009

level mod: press R to warp

D0281251 0010
8037E8F4 0001
D0281251 0010
8037E8F5 00xx-level
D0281251 0010
8037E8F6 00yy-part of level

codes are from:
http://www.rarewitchproject.com/forums/showthread.php?t=6362

N64 N64 GBA
just scroll down and there are several codes for BK,BT,and BK:GR

cutscene numbers:you can't move around in cutscenes with this code

001e - Intro - Start - Nintendo
001f - Intro - Start - Rareware
0020 - Intro - End Scene 2 : Not 100 007b - Intro - Grunties Lair 1 - Scene 1 0081 - Intro - Grunties Lair 2
0082 - Intro - Grunties Lair 3 - Machine 1
0083 - Intro - Grunties Lair 4 - Game Over
0084 - Intro - Grunties Lair 5
007c - Intro - Inside Banjo's Cave 1 - Scenes 3,7
0089 - Intro - Inside Banjo's Cave 2
008a - Intro - Inside Banjo's Cave 3
007d - Intro - Spiral 'A' - Scenes 2,4
007e - Intro - Spiral 'B' - Scenes 5,6
0085 - Intro - Spiral 'C'
0086 - Intro - Spiral 'D'
0087 - Intro - Spiral 'E'
0088 - Intro - Spiral 'F'
0094 - Intro - Spiral 'G'
0095 - Intro - End Scene 3 : All 100
0098 - Intro - Grunty Threat 1
0099 - Intro - Grunty Threat 2
0096 - Intro - End Scene 0097 - Intro - End Scene 4

level numbers:

001e - Intro - Start - Nintendo
001f - Intro - Start - Rareware
0020 - Intro - End Scene 2 : Not 100
007b - Intro - Grunties Lair 1 - Scene 1
0081 - Intro - Grunties Lair 2
0082 - Intro - Grunties Lair 3 - Machine 1
0083 - Intro - Grunties Lair 4 - Game Over
0084 - Intro - Grunties Lair 5
007c - Intro - Inside Banjo's Cave 1 - Scenes 3,7
0089 - Intro - Inside Banjo's Cave 2
008a - Intro - Inside Banjo's Cave 3
007d - Intro - Spiral 'A' - Scenes 2,4
007e - Intro - Spiral 'B' - Scenes 5,6
0085 - Intro - Spiral 'C'
0086 - Intro - Spiral 'D'
0087 - Intro - Spiral 'E'
0088 - Intro - Spiral 'F'
0094 - Intro - Spiral 'G'
0095 - Intro - End Scene 3 : All 100
0098 - Intro - Grunty Threat 1
0099 - Intro - Grunty Threat 2
0096 - Intro - End Scene
0097 - Intro - End Scene 4
008c - Spiral Mountain - Banjo Cave
0091 - Spiral Mountain - Banjo Cave Save
0001 - Spiral Mountain - Spiral Mountain
0002 - Mumbo's Mountain
000c - Mumbo's Mountain - Termite Hill
000e - Mumbo's Mountain - Shamen Hut
0007 - Treasure Trove Cove
0005 - Treasure Trove Cove - Pirate Rusty Bucket Bay Hold
0006 - Treasure Trove Cove - Crab Shell
008f - Treasure Trove Cove - Sea Castle
000a - Treasure Trove Cove - Sand Castle
000b - Clankers Cavern
0021 - Clankers Cavern - Inside A
0022 - Clankers Cavern - Inside B
0023 - Clankers Cavern - Inside C
000d - Bubble Gloop Swamp
0010 - Bubble Gloop Swamp - Crocodile Head
0011 - Bubble Gloop Swamp - Turtle
0047 - Bubble Gloop Swamp - Shamen Hut
0012 - Gobi Valley
0013 - Gobi Valley - Pyramid 1 (Match the pairs)
0014 - Gobi Valley - Pyramid 2 (Maze)
0015 - Gobi Valley - Pyramid 3 (Water)
0016 - Gobi Valley - Pyramid 4 (Snake)
001a - Gobi Valley - Sphinx
0092 - Gobi Valley - Secret Chamber
001b - Mad Monster Mansion
001c - Mad Monster Mansion - Organ
001d - Mad Monster Mansion - Cellar
0024 - Mad Monster Mansion - Ouija Board
0025 - Mad Monster Mansion - Well
0026 - Mad Monster Mansion - Dining Room
0028 - Mad Monster Mansion - Room 1
0029 - Mad Monster Mansion - Room 2
002a - Mad Monster Mansion - Room 3 : Fireplace
002b - Mad Monster Mansion - Church
002c - Mad Monster Mansion - Room 4 : Bathroom
002d - Mad Monster Mansion - Room 5 : Bedroom
002e - Mad Monster Mansion - Room 6 : Floorboards
002f - Mad Monster Mansion - Barrel
0030 - Mad Monster Mansion - Shamen Hut
008d - Mad Monster Mansion - Septic Tank
0031 - Rusty Bucket Bay
008b - Rusty Bucket Bay - Anchor room
0034 - Rusty Bucket Bay - Prop Room
0035 - Rusty Bucket Bay - Warehouse 1
0036 - Rusty Bucket Bay - Warehouse 2
0037 - Rusty Bucket Bay - Container 1
0038 - Rusty Bucket Bay - Container 3
0039 - Rusty Bucket Bay - Crew Cabin
003a - Rusty Bucket Bay - Hold
003b - Rusty Bucket Bay - Store Room
003c - Rusty Bucket Bay - Galley
003d - Rusty Bucket Bay - Navigation Room
003e - Rusty Bucket Bay - Container 2
003f - Rusty Bucket Bay - Captain's Cabin
0053 - Freezeezy Peak - Inside Xmas Click Clock Wood
0041 - Freezeezy Peak - Igloo
0027 - Freezeezy Peak
0048 - Freezeezy Peak - Shamen Hut
007f - Freezeezy Peak - Wozza Cave
0040 - Click Clock Wood - Start
0043 - Click Clock Wood - Main (Spring)
0044 - Click Clock Wood - Main (Summer)
0045 - Click Clock Wood - Main (Autumn)
0046 - Click Clock Wood - Main (Winter)
004a - Click Clock Wood - Shamen Hut (Spring)
004b - Click Clock Wood - Shamen Hut (Summer)
004c - Click Clock Wood - Shamen Hut (Autumn)
004d - Click Clock Wood - Shamen Hut (Winter)
005a - Click Clock Wood - Wasp Hive (Summer)
005b - Click Clock Wood - Wasp Hive (Spring)
005c - Click Clock Wood - Wasp Hive (Autumn)
005e - Click Clock Wood - Squirrel House (Spring)
005f - Click Clock Wood - Squirrel House (Summer)
0060 - Click Clock Wood - Squirrel House (Autumn)
0061 - Click Clock Wood - Squirrel House (Winter)
0062 - Click Clock Wood - Squirrel Room 1 (Winter)
0063 - Click Clock Wood - Squirrel Room 2 (Autumn)
0064 - Click Clock Wood - Squirrel Room 2 (Winter)
0065 - Click Clock Wood - Top (Spring)
0066 - Click Clock Wood - Top (Summer)
0067 - Click Clock Wood - Top (Autumn)
0068 - Click Clock Wood - Top (Winter)
0069 - Grunty's Lair - Flr 1, Area 1 : Mumbo
006a - Grunty's Lair - Flr 1, Area 2
006b - Grunty's Lair - Flr 1, Area 3
006c - Grunty's Lair - Flr 1, Area 3a : Cauldron
006d - Grunty's Lair - Flr 1, Area 4 : Pirate Rusty Bucket Bay
0070 - Grunty's Lair - Flr 1, Area 5 : Pipes room
0071 - Grunty's Lair - Flr 1, Area 6 : Grunty's Lair statue
0072 - Grunty's Lair - Flr 1, Area 7 : Bubble Gloop Swamp/Freezeezy Peak
006e - Grunty's Lair - Flr 2, Area 1 : Sand Chamber
006f - Grunty's Lair - Flr 2, Area 2 : Spooky/Advent
0074 - Grunty's Lair - Flr 2, Area 4 : Dark room
0075 - Grunty's Lair - Flr 2, Area 5 : Crypt outside
007a - Grunty's Lair - Flr 2, Area 5a : Crypt inside
0076 - Grunty's Lair - Flr 3, Area 1
0077 - Grunty's Lair - Flr 3, Area 2 : Rusty Bucket Bay side
0078 - Grunty's Lair - Flr 3, Area 3
0079 - Grunty's Lair - Flr 3, Area 4 : Click Clock Wood trunks
0080 - Grunty's Lair - Flr 3, Area 4a
008e - Grunty's Lair - Flr 4, Area 1 : Quiz Room
0093 - Grunty's Lair - Flr 5, Area 1 : Gruntie's rooms
0090 - Grunty's Lair - Battlements

Enable Code Must Be On!
DE000400 0000
8124B728 1700
812864E4 1700
812D2E00 1300

Infinite Health
803851A3 0008
803851A7 0008

Infinite Lives
803851AB 0009

Flying Banjo Kazooie
D02804C9 0020
8137B6BC 43E0

While playing Press L to make Banjo and Kazooie fly as high as you want let go of L and they will fall. Infinite Air
813851AE 0E10

Infinite Eggs
80385187 0063

Time Is Always 0:00:08
8138524C 4100

Maximum Health
803851A7 0008

Infinite Mumbo Tokens
803851E7 0063

Infinite Jiggys
803851EB 0063

Infinite Notes
80385183 0063

Have All Jinjos
8038519B 0010

Infinite Gold Feathers
80385193 0063

Infinite Red Feathers
8038518F 0063

Must Be On
de0004000000
8124c9d81700
812876a41700
812d3dc01300
Infinite Lives 80385f8b0009
Infinite Health 80385f830008 80385f870008
Infinite Red Feathers 80385f6f0063
Infinite Gold Feathers 80385f730063
Infinite Air 81385f8e0e10
Extra Notes 80385f630063
Infinite Eggs 80385f670063
Extra Jiggies 80385fcb0063

All Easter Eggs:
D0285914 0008
8037D167 0040

When Mumbo shows you the picture and you are on top of the mountain in Sharkfood Island, press Up to get the egg.

Turn off the Nintendo 64 when the game shows you the ice key.

Start the game again and you will be able to get them.

extra jiggies 80385fcd0063

extra notes 80385f630063