Used BMW i4 Catalytic Converter

No — the BMW i4 is a fully electric vehicle and has no internal combustion engine, exhaust system, or catalytic converter of any kind. Because there are no exhaust gases to treat, none of the i4's variants (eDrive35, eDrive40, M50) were ever fitted with a catalytic converter. If you've been quoted for one against an i4 registration, it's worth double-checking whether the registration has been misread or misrecorded, as the i4 shares its platform with petrol-engined models like the 4 Series Gran Coupé (G26) which do have catalysts.

The i4 has no exhaust system at all, so there is no catalytic converter, DPF, lambda sensor, or exhaust manifold to source. The drivetrain produces no emissions, meaning the only 'exhaust-adjacent' components are cosmetic blanking panels at the rear where exhaust tips would sit on a petrol model. If your concern is an MOT-related emissions failure, it's worth confirming with DVLA or your garage that the vehicle registered to your plate is genuinely an i4 and not a petrol or hybrid 4 Series variant.

No — the i4 has no exhaust system to fit one to, so the question of interchange doesn't arise. The petrol G26 4 Series Gran Coupé shares its bodyshell with the i4 but has an entirely different underbody layout, and a catalyst from that car has no mounting point or purpose on an electric i4. If you own a petrol G26 4 Series Gran Coupé and need a catalytic converter for it, that's a separate search and a breaker can help you match it by engine code and registration.

Neither the i4 M50 nor the eDrive40 nor any other i4 variant has a catalytic converter, as all versions of the i4 are fully battery-electric with no combustion engine or exhaust. Trim level makes no difference here — the absence of a catalyst applies equally across the entire i4 range. If you're comparing the M50 and eDrive40 for a different part, a breaker will be able to advise on what does and doesn't interchange between those two variants.

This is almost certainly an error, as the i4 is a fully electric car and cannot have a faulty catalytic converter because it doesn't have one. It's possible the diagnostic has been run against the wrong vehicle, or there has been a confusion with a different car on the same registration in a garage management system. We'd recommend querying this directly with your garage and confirming the vehicle details, as no breaker will be able to supply a part that was never fitted to this model.