P0420/p0430

apextc

I want to resurrect this thread as I am having the same issue.

Situation: I am getting a P0420 / 0430 error code.

My car: 2009 Sport / MT/ 79K with ONLY bolt-ons which are Takeda Intake, Full Stillen Dual Exhaust System.

I got the car checked at a mechanic and in summary, it seems like its a step by step process to figure out the root cause, which is to TRY:

1- change 02 sensors
2- Buy a check engine light eliminator from BLOX racing
3- Take it to a trusted performance shop

Anyone in the Chicagoland area/Naperville help a brotha out?





What causes the P0420 code?

Damaged muffler or leaks in the muffler
Damaged exhaust manifold or leaks in the exhaust manifold
Damaged exhaust pipe or exhaust pipe leaks
A misfire in the engine
Oil contamination in catalytic converter
Faulty catalytic converter (most common)
Faulty engine coolant temperature sensor
Faulty front oxygen sensor
Faulty rear oxygen sensor
Damaged oxygen sensor wiring
Oxygen sensor wiring that is not properly connected
Damaged oxygen sensor connectors
A fuel injector that is leaking
Fuel pressure that is high
Use of the wrong kind of fuel (using leaded fuel instead of unleaded fuel)