Emission components are typically covered by a warranty extending beyond the bumper-to-bumper warranty, varying by state of sale; consulting a BMW dealership before pursuing repairs on emission or fuel controls is advised. The crankcase emission control system requires no routine attention apart from periodic checks on hose integrity. For charcoal canister replacement, under the vehicle, the canister is accessible beneath the rear, necessitating rear jacking and secure jackstand support. Remove the cover and plastic panel (if present) at the right side of the spare wheel well, disconnect hoses with plastic locking clips (or use a flare nut wrench for M56 engine models), and note hose positions for reinstallation. Unscrew securing screws and withdraw the canister/bracket assembly, ensuring correct hose reconnection. For purge solenoid valve replacement, situated beneath the intake manifold, remove the heater/ventilation inlet air ducting by rotating fasteners, undoing retaining clips, unscrewing screws, and pulling the inlet ducting out. Reach under the manifold, disconnect the valve wiring connector, depress the locking catch to disconnect the hoses, and remove the valve from the rubber holder. Installation is in reverse. Catalytic converter replacement involves integral exhaust manifold replacement. The secondary air injection system components consist of the air injection valve located above the exhaust manifold on the right-side cylinder head and the air pump situated on the right-hand inner fender. Disconnect hoses and remove the air injection valve by unscrewing retaining nuts, then remove the pump by loosening the clamp and disconnecting the hose. Installation for both components is the reverse process, securing with retaining nuts and fasteners, respectively. Note that M56 engine models feature a MAF sensor in the duct leading to the air pump from its air filter.