Question

2002 Infiniti I35 with engine codes P1800, P0021, and P0011 all three codes at one time. which one do I need to replace?

Answer 1

Do you have any driveability problems? If you don't, then you could start by clearing the codes and changing the engine oil. Make sure you use the factory recommend oil weight 5W-30.

P1800 2002 INFINITI I35 - Variable Intake Air System Control Solenoid Valve Circuit
Read more: https://www.autocodes.com/p1800_2002_infiniti_i35.html

P0011 2002 INFINITI I35 - Intake Valve Timing Control Performance Bank 1
Read more: https://www.autocodes.com/p0011_2002_infiniti_i35.html

P0021 2002 INFINITI I35 - Intake Valve Timing Control Performance Bank 2
Read more: https://www.autocodes.com/p0021_2002_infiniti_i35.html