204 appears to be correct. Perhaps K&N has updated their apps.
K&NKN-191 Product Specifications Product Style: Oil FiltersHeight: 2.992 in (76 mm)
Outside Diameter: 2.807 in (71 mm)
Thread Inside Diameter: M20 x 1.5
PSI Relief Valve: 15.08
Anti Drain Back Valve: Yes
Style: Canister
Weight: 0.6 lb (0.3 kg)
Product Box Length: 3 in (76 mm)
Product Box Width: 3 in (76 mm)
Product Box Height: 3.25 in (83 mm)
KN-204 Product Specifications Product Style: Oil FiltersHeight: 2.953 in (75 mm)
Outside Diameter: 2.673 in (68 mm)
Thread Inside Diameter: M20 x 1.5
Anti Drain Back Valve: Yes
Style: Canister
Weight: 0.5 lb (0.2 kg)
Product Box Length: 2.75 in (70 mm)
Product Box Width: 2.75 in (70 mm)
Product Box Height: 3 in (76 mm)
In the past, I have used a KN-303 with no problems.
KN-303 Product Specifications Product Style: Oil FiltersHeight: 3.346 in (85 mm)
Outside Diameter: 2.673 in (68 mm)
Thread Inside Diameter: M20 x 1.5
PSI Relief Valve: 18.13
Anti Drain Back Valve: Yes
Style: Canister
Weight: 0.6 lb (0.3 kg)
Product Box Length: 2.75 in (70 mm)
Product Box Width: 2.75 in (70 mm)
Product Box Height: 3.5 in (89 mm)