Bobcat S740 P0421 Error Code
P0421 Error Code
DOC Efficiency Fault (During Regen) is the main cause of P0421 error.A significant number of consequences can be suffered due to an overheating engine with code P0421. The problem might be a blown gasket or something related to the fuel tank.
Tip For S740 Model
It is recommended in cold weather to cycle the glow plugs twice before attempting to start the engine. This will allow for additional heating time for cold weather starting.