BN-521 Info Page
(BN-521A Pictured)
| Part Number | OEM # | Length | Inlet/Outlet | Sensor | Additional Info |
| BN-521 | |||||
| BN-521A | 48" | shield bolts on | |||
| BN-521B | 50" | shield crimps on, oval body, (up to 1996 models) | |||
| BN-521C | U98 | 55" | shield crimps on, round body, (1996+ models) | ||
| BN-521D | 05, 143290 | 8 1/2" | straight 2 bolt flat flange in, straight 2 bolt flat flange out | 1 7/8" opening & 2" opening | |
| BN-521E1 | 41" | 2 bolt bell in, 2 bolt out | w/out sensor | 12" round body | |
| BN-521E2 | 41 1/2" | 2 bolt in, 2 bolt out | w/sensor 9" below inlet | 12" round body | |
| BN-521F1 | GL9 | 51 1/2" overall, 1 1/4" outlet | 2 bolt flat flange w/lip in, 2 bolt flat flange w/ 2 1/4" lip out | 1 sensor 3/4" behind front flange | 10" round body, 40 1/2" neck, w/flex in front neck, w/hanger on neck |
| BN-521F2 | GL9 | 49 3/4" overall, 3" outlet | 2 bolt flat flange w/lip in, 2 bolt flat flange w/2" lip out | 1 sensor 3/4" behind front flange | 10" round body, 37" neck w/flex, w/hanger on neck |
| BN-521F3 | GL9 | 50" overall, 1" outlet | 2 bolt flat flange w/lip inlet, 2 bolt flat flange w/lip out, 2 1/4" diameter lip outlet | 1 sensor 3" behind flex | 10" round body, 39" neck w/flex, w/hanger on neck |
| BN-521F4 | GF5 | 58 1/2" overall, 3 1/2" outlet | 2 bolt flat flange w/lip inlet (2 1/4" lip diameter), 2 bolt flat flange w/lip inlet (2 1/4" lip diameter) | 1 sensor 2" from flex | 14 1/2" round body, 36 1/2" neck w/flex & hanger on neck |
| BN-521F5 | GL9 | 51" overall length | 2 bolt in/2 bolt out, both with lips | 1 sensor 2" behind flex | 37" neck w/flex, hanger between flex and body, 10" round body |
| Part Number | OEM # | Length | Inlet/Outlet | Sensor | Additional Info |
| BN-521F6 | 51" overall length | 2 bolt in/2 bolt out, both with lips | 1 sensor 1 1/4" behind flex | 37" neck w/flex, hanger between flex and body, 12 1/4" round body, hanger over top of flex | |
| BN-521F7 | 48 1/4 overall length | 2 bolt in, 2 bolt out, both with lips | 1 sensor 1 1/2" below flex | 33 1/4" neck w/flex, hanger between flex and body, hanger over top of flex, 12" round body | |
| BN-521G1 | 8J2HU (on rear flange) | 52" | 2 bolt bell in, 2 bolt flat flange out | w/out sensor | 12" round body |
| BN-521G2 | 53" | 2 bolt in, 2 bolt out | w/sensor 18 1/2" below inlet | 12" round body | |
| BN-521H1 | 37" | 2 - 3 bolt flange inlets, 2 bolt flange out | w/out sensor | 12" round body, 1 - 5 1/2" flex, 1 - 4 1/2" flex | |
| BN-521H2 | 37" | 2 - 3 bolt inlet, 2 bolt outlet | w/out sensor | 12" round body, 2 x 5" flex | |
| BN-521I1 | GA5, GL9 | 50 1/2" | 2 - 2 bolt flange inlets, 2 bolt flange out | 1 sensor 1" from 2 bolt flange, 1 sensor 9" from 2 bolt flange | TOYOTA, 1 flex 7" long, |
| BN-521I2 | X18 | 50 3/4" | 2 - 2 bolt flange inlets, 2 bolt flange out | 1 sensor 1" from 2 bolt flange, 1 sensor 9" from 2 bolt flange | TOYOTA, 1 flex 7" long, |
| BN-521J1 | 8U8GU (on rear flange) | 51" | 3 bolt flange in, 2 bolt flange out | 1 sensor 8" from body | 9" flex, 12" round body, smooth center of body 2 1/2" |
| BN-521J2 | 52" | 3 bolt flange in, 2 bolt flange out | 1 sensor 8" from body | 8" flex, 12" round body, smooth center of body 5", BN-521J2 has different clock position than BN-521J1 or J3 | |
| Part Number | OEM # | Length | Inlet/Outlet | Sensor | Additional Info |
| BN-521J3 | 53" | 3 bolt flange in, 2 bolt flange out | 1 sensor 8" from body | 8" flex, 12" round body length | |
| BN-521K | 41 1/2" | 2 - 3 bolt flange inlets, 2 bolt outlet | 1 sensor 3 3/4" below flange | 12" round body, 2 - 6" flexes | |
| BN-521L1 | 7S21A0E | 25 3/4" | 2 bolt inlet, 2 bolt outlet | 1 sensor 3 1/4" from body | 12" round body |
| BN-521L2 | 27 1/2" | 2 bolt inlet, 2 bolt outlet | 1 sensor 2 1/2" from body | 12" round body | |
| BN-521L3 | 28 1/2" | 2 bolt inlet, 2 bolt outlet | 1 sensor 2 1/2" from body | 12" body | |
| BN-521L4 | 29 1/2" | 2 bolt inlet, 2 bolt outlet | 1 sensor 3" from body | 12" round body | |
| BN-521M | SAME AS BN-867D | ||||
| BN-521N | U50 | 58 1/2" | 2 bolt in, 2 bolt out | 1 sensor 3" below flex, 1 sensor 6 1/2" below body | 7" flex |
| BN-521O | T34 | 49" | 2 bolt in, 2 bolt out | 1 sensor 2" below inlet, 1 sensor 4" below body | |
| BN-521LP | X24 | 3 bolt in, 2 bolt out | 1 sensor below inlet flange, 1 sensor between bodies | hanger below rear body, Toyota | |
| BN-521RP | X24 | 3 bolt in, 2 bolt out | 1 sensor below inlet flange, 1 sensor between bodies | ||
| BN-521Q | T61 | 3 bolt in, 2 bolt out | 1 sensor in front pipe, 1 sensor in rear pipe | ||
| BN-521R | JA6N3 | 3 bolt in, 2 bolt out | 1 sensor behind flex | flex in front pipe, flattened pipe between flex and body, hanger bolt in middle of flattened pipe | |
| Part Number | OEM # | Length | Inlet/Outlet | Sensor | Additional Info |