B0421 Seat Altea DTC Code

Seat Altea Engine Specifications:

Engine Type :	Single Cylinder Engine
Cylinder Type :	Opposite Piston Engine
Engine Air Intake Process :	Naturally Aspirated

Your Seat Altea engine control system detects a problem, the computer stores the diagnostic trouble code B0421 in its memory. To figure out what is wrong with your vehicle you must first extract the B0421 DTC For Seat Altea.

To solve B0421 Seat Altea problem, you'll have to remove the muffler, crankcase and other components blocking the valve chamber. Then, remove the cylinder head bolts (label for easy re-installation) Adjust the jaws of the valve spring compressor until they touch the top and bottom of the valve chamber Push the tool in to compress the spring and tighten the jaws Remove the retainers and lift out the valves , compressors and springs

B0421 Seat Altea DTC Meaning

B	Body Code - Problem is antilock brake system, electronic suspension and steering systems.
0	SAE - Generic
4	Fuel And Air Metering (Injector Circuit Malfunctions Only)
2	Cruise Control Servo Indicates Low
1	PCM Stack Overrun

If your vehicle failed a B0421 Seat Altea test and the B0421 Check Engine Light is NOT on, chances are you have a problem with the OBDII system, a burned out MIL lamp, or a faulty catalytic converter. The converter is essentially an afterburner that cleans up the exhaust after it exits the engine. The OBDII system uses B0421 a ownstream oxygen sensor to monitor the efficiency of the converter, and it should detect a drop in converter efficiency if the converter has been contaminated or is failing (ignition misfiring, leaky exhaust valves, and oil burning can all damage the converter). What you want to look B0421 DTC For Seat Altea: Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression.