MustangMike2016

2016 Mustang Specs- Borla Atak 3" , Kooks 1 7/8 headers catted , Jlt cold air intake, 90 MM BBK Throttle body, and a sct tune.

Ok, So this is my first time here looking for some help and i appreciated any help i get.

I have a Check engine light reading P0420 and P0430, i tried to clear the code but it returns in a few hours. These take away from power of the car. Any info is great thanks guys !


-Mike

krssrls

A code P0420 may mean that one or more of the following has happened: Leaded fuel was used where unleaded was called for A damaged or failed oxygen sensor (HO2S) Downstream oxygen sensor (HO2S) wiring damaged or connected improperly The engine coolant temperature sensor is not working properly Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe Retarded spark timing The oxygen sensors in front and behind the converter are reporting too similar of readings Leaking fuel injector or high fuel pressure Cylinder misfire Oil contamination Possible Solutions Some suggested steps for troubleshooting a P0420 error code include: Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required. Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady). Inspect the downstream heated oxygen sensor (HO2S), replace if necessary Replace the catalytic converter Overall probably the biggest mistake vehicles owners make when they have a P0420 code is to simply replace an oxygen sensor (H02S). It is important to do proper diagnosis so you're not wasting money replacing parts unnecessarily. We strongly recommend that if you need to replace the catalytic converter that you replace it with an OEM unit. Second choice would be a high-quality replacement part. There are many stories in our forums where folks replaced the cat with a cheaper aftermarket one only to have the code return shortly thereafter. One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type

Read more at: http://www.obd-codes.com/p0420
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krssrls

You will likely not notice any drivability problems, although there may be symptoms such as a rough/hard idle when cold. Causes A code P0430 may mean that one or more of the following has happened: The catalytic converter is no longer functioning properly An oxygen sensor is not reading (functioning) properly There is an exhaust leak Possible Solutions First, inspect for exhaust leaks. Next step is to measure the voltage at the oxygen sensor on Bank 2. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it. One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into. Register now to ask a question (free)

Read more at: https://www.obd-codes.com/p0430
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jz78817

Those are "catalyst efficiency below threshold" codes. The aftermarket cats you put on are pieces of s**t which don't do their jobs very well.

Derf00

The kooks headers probably use Hi-flo cats. That means that the exhuast gases do not spend enough time in the cat to get heated enough to burn off all of the emissions that the cars PCM is expecting, thus the P0430 code for catalytic efficiency. The P0420 code is also most likely related since again, the 02 sensor is not responding as expected.

This is why Hi flo cats do not always work. You may need to have the tune shut off the rear O2 sensors to avoid codes...unless your state does an OBDII check.

Derf00

If Kooks supplied them, I'm not so sure they are crap, it's just well...they are Hi-flo which means he needs to either find a way to reduce his emissions upstream (dyno tune) or turn off the rear O2 sensors to avoid the code. He may be running rich as headers don't often do well with generic tunes and get into the realm where a dyno tune is better.