1998 328i.. Got a 1421 and 1423 code...not sure where to start...
1997 BMW 328I 2.8L
MIL is on with trouble codes P1421 and P1423, for incorrect secondary airflow on both cylinder banks.
1. Perform a functional test of the Air Injection Reaction (AIR) system. Tee a vacuum gauge into the vacuum hose attached to the diverter valve, located on the cylinder head towards the front of the engine.
2. Allow the vehicle to sit over night. Start the engine (cold) while monitoring the amount of vacuum on the gauge at startup. At temperatures from -10 to 40 degrees Celsius, there should be at least 17 inches of vacuum. At the same time, the AIR pump should run and pump a large volume of air into the exhaust.
Air Pump Relay
Restricted Cylinder Head
These codes are related to a problem detected in the Secondary Air Injection system. Scan tools with BMW software include a feature to command the AIR pump on and off. The pattern failures for these codes are the AIR pumps due to leaks in the diverter valve and moisture or condensation in the AIR pump.
Possible fix but not all items. Just areas to look at:
A.I.R. Pump, Air Injection Reaction Diverter (AIRD) Valve
Air Injection Reaction Diverter (AIRD) Valve
Check Valve, Secondary Air Pump
Diverter Valve Vacuum Lines
Jul 04, 2009 |
1997 BMW 328