This MagnaFlow OEM Grade catalytic converter fits Bank 2 (cylinders 4-6) of the S55 6-cylinder turbocharged engine on F87 M2 Competition (2019, 2020, 2021), F80 M3 Sedan (2015, 2016, 2017, 2018), and F82/F83 M4 (2015, 2016, 2017, 2018, 2019, 2020)
Replaces BMW part number 18327848044 (18-32-7-848-044).
This replacement part is designed to meet or exceed Federal emissions requirements set forth by the EPA, complying with legal standards for OBDII Federally registered vehicles with Federal/EPA Emission systems. Not for sale in California or in other states that have adopted California regulations for catalytic converters.
Catalytic converters rarely fail on their own.
In most cases, another issue has caused the catalytic material to be contaminated, overheated, or damaged, leading to failure. The most typical failure comes from a failed primary/front O2 sensor, which cause the engine to run rich (reducing fuel economy), which also melts the catalyst. Replacing your failed catalyst without solving the root cause of failure will void any warranty and significantly reduce lifespan of the replacement catalyst. It is the customer's responsibility to diagnose and determine the root cause of a catalyst-related engine code. Before spending thousands of dollars on a new catalytic converter, make sure you have considered and investigated all other potential sources for your fault codes - oxygen (O2) sensors, cooling system, intake or exhaust leaks, fuel injection, vacuum, secondary air system, and other emissions-related equipment. Returns of this product are limited to quality and workmanship issues only.Federal vs California Spec.
Catalytic converters must be matched to the vehicle build specification and/or the region where it will be used. Using a non-California cat on a California-spec car will result in failure of emissions inspection and possibly even poor drivability, fault codes, and a check engine light for incompatible parts. Your vehicle spec can be found on an emissions label on the underside of your hood. California-spec cats are more expensive but have premium catalytic material and a longer warranty.
California (CARB grade or CARB certified): you must use a California-spec cat. A California-spec cat can be used in all 50 states, regardless of original spec.Colorado, Maine, or New York:
state law requires a CARB-certified cat for all new sales beginning January 1, 2023, regardless if the car was built as a “California version” or not. The previous "OEM grade" will no longer be accepted in these states.All other states (Federal) (MagnaFlow HM or Standard grades):
the “Federal” spec is acceptable, however, using a non-California cat on a California-spec car may cause poor drivability, fault codes, and a check engine light for incompatible parts.
F87 (2016-2021) > M2 Competition S55 (2019+)
F80 (2015-2018) > M3 (2015-2018)
F82 / F83 (2015-2020) > M4 (2015-2020)
F82 / F83 (2015-2020) > M4 GTS