Help Diagnosing Multiple CEL Codes on 2015 Mustang 6 Cylinder

[oelmustang]

Hey everyone,


I’ve got a 2015 Ford Mustang with the 3.7 L and about 130,000 miles on it. The Check Engine Light came on (Was always on due to aftermarket exhaust), and my OBD-II reader threw a ton of codes at me:

• P0420 – Catalyst System Efficiency Below Threshold (Bank 1)
• P0430 – Catalyst System Efficiency Below Threshold (Bank 2)
• P0056 – O₂ Sensor Heater Control Circuit High (Bank 2 Sensor 2)
• P0135 – O₂ Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
• P0141 – O₂ Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
• P0155 – O₂ Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
• P0010 – Camshaft Position Actuator Circuit (Bank 1)
• P0013 – Camshaft Position Actuator “B” Circuit/Open (Bank 1)
• P0020 – Camshaft Position Actuator Circuit (Bank 2)
• P0023 – Camshaft Position Actuator “B” Circuit/Open (Bank 2)
• P0443 – EVAP Purge Control Valve Circuit Malfunction
• P0446 – EVAP Vent Control Circuit Malfunction

Tuned to 87 by BAMA, short headed, has cats.
EVAP valve was changed 8 months ago. All these codes showed up suddenly.
Loss of acceleration sometimes.

Anyone knows how to fix this or what the cause of it is?

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[Call_Me_Bruce]

I’d think it is a harness problem. Jack it up get under it and follow the wiring harness from the cats forward and look for breaks. Check the grounds as well.

 

[NTXChris]

I’d think it is a harness problem. Jack it up get under it and follow the wiring harness from the cats forward and look for breaks. Check the grounds as well.

My thoughts as well.

You stated that your CEL has been on since the aftermarket exhaust was installed, but you still have cats? Sounds like something was damaged during the exhaust install. A catback exhaust shouldn't trigger a CEL unless something was damaged; you wouldn't be touching/modifying the emissions control system at all in that scenario.

That being said, I'd start with the connector to the EVAP purge valve - it was the last thing touched.

 

[oelmustang]

Great thank you I will check it out. Is there an easy way to check for damaged wires?

 

[oelmustang]

I checked out fuse box 2 fuses are blown, replaced and drove a bit and then blown again, checked wires all good except O2 sensor bank 2 driver seat as seen below shows touching.

Last modification done was changed the rear side markers but I don’t think this is issue.

Battery and alternator are good.

and bent I don’t know if this is causing the issue, attached the new codes.

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