Persistent Engine light - Non OEM Exhaust

[Royd]

My C8 has a Non OEM Hennessey Exhaust which endlessly lights up the orange Engine Alert indicator.

My OBD2 reader shows related two codes;
P12F5 - Cylinder Deactivation Exhaust Flow Valve Feedback Circuit High Duty Bank 2
P12EAC - Cylinder Deactivation Exhaust Flow Valve Closed Position Bank 1

The engine light reappears very soon after clearing those codes as these [Permanent] codes get repeated..

The effects of these codes can be engine running rough, high fuel consumption and other problems which seemingly should not be ignored in the longer term.

I notice that of the four exhaust outlets, one on the right and one on the left blackness soon after cleaning indicating supposedly a mixture over rich. And loss of the 4 modes of exhaust sound control, Stealth, etc., which can be tolerated for the extra HP.

My Chev/Corvette dealer seems unwilling to have anything to do with Non OEM exhausts. They say that to clear the problem, change back to an OEM exhaust [and lose the associated 21 HP improvement advertised for the Hennessey].

Guidance from CCF membership welcome please.

 

[DW Ruby]

My C8 has a Non OEM Hennessey Exhaust which endlessly lights up the orange Engine Alert indicator.

My OBD2 reader shows related two codes;
P12F5 - Cylinder Deactivation Exhaust Flow Valve Feedback Circuit High Duty Bank 2
P12EAC - Cylinder Deactivation Exhaust Flow Valve Closed Position Bank 1

The engine light reappears very soon after clearing those codes as these [Permanent] codes get repeated..

The effects of these codes can be engine running rough, high fuel consumption and other problems which seemingly should not be ignored in the longer term.

I notice that of the four exhaust outlets, one on the right and one on the left blackness soon after cleaning indicating supposedly a mixture over rich. And loss of the 4 modes of exhaust sound control, Stealth, etc., which can be tolerated for the extra HP.

My Chev/Corvette dealer seems unwilling to have anything to do with Non OEM exhausts. They say that to clear the problem, change back to an OEM exhaust [and lose the associated 21 HP improvement advertised for the Hennessey].

Guidance from CCF membership welcome please.

My opinion: Lose the exhaust.

 

[Murray20c8]

Seems weird if it's just a cat back. Is it straight through without the Z51 exhaust valves? Sounds like you don't have much choice. remove it or find a tech who can look at it.

 

[PapaSmurf]

Your car may need a set of simulators from Paragon to get rid of the check engine light.

 

[DynamicCaps]

Your car may need a set of simulators from Paragon to get rid of the check engine light.

Lose it, or this

 

[Murray20c8]

Your car may need a set of simulators from Paragon to get rid of the check engine light.

You mean you have to replace your stock O2's with simulators?
Sounds strange. How far away from the cats are the secondary O2's?

 

[scraze66]

You mean you have to replace your stock O2's with simulators?
Sounds strange. How far away from the cats are the secondary O2's?

He is talking about the AFM and NPP valve simulators.

 

[Paul C7 to C8]

I had the exact same thing happen to me with my Borla system. The issue was traced to one of the catalytic converters which was replaced and issue resolved. Dealer had no prob with replacing the cat.