P0420 code on new '08

black08

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Took delivery of a new ACR last Thursday. Prior to delivery, I had the dealership install the Belanger header/exhaust system. I have to say, it sounds awesome and my wife and I both love it and the car.

Unfortunately, at 200 miles, the MIL came on. I ran out and bought a code reader and extracted one code; P0420.:(

Will be contacting the dealer this week to arrange to take the car back to find out what is wrong. Hopefully, between the dealer and Lou, they can figure it out. Kind of disappointing this early in the game but I do love the sound of the Belanger system.
 

Garron

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P0420 is a catalyst efficieny code. May have to do with your exhaust upgrade. The following can cause this code to set, Exhaust leak, oxygen sensor, or catalytic converter. Maybe clear the code and see if it resets?
 

Grant

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In addition to what Garron posted, the code can be thrown if high-flow cats (or any cats really, its just that OE ones generally don't have any problems) aren't getting hot enough. Simply driving it harder can take care of that. If you're taking it easy during break-in, you might find you can clear the code and it will never come back afterwords.
 
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black08

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Garron and Grant...thank you very much for the info. Much appreciated! Grant, I am hoping you are right. We have been taking it easy on the car and not driving hard. We plan on taking it easy for the first 500 miles, then oil change, then going for broke.

In the meantime, I cleared the code and we'll keep our fingers crossed.
 

cheryl mccally

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Garron and Grant...thank you very much for the info. Much appreciated! Grant, I am hoping you are right. We have been taking it easy on the car and not driving hard. We plan on taking it easy for the first 500 miles, then oil change, then going for broke.

In the meantime, I cleared the code and we'll keep our fingers crossed.
I have had the same code light problem with my '08 ACR. Once I found out it was just an exhaust sensor problem, I just kept driving and ignored it, my tech would clear it when I went in for service. Now when the light comes on, if it's just the exhaust sensor, the light will clear itself usually in less than 24 hours. My Viper tech said that the ECU has to actually learn what is the new normal when you change the stock headers/exhaust to the Belangers. So keep the faith, at least for me, the problem has finally resolved itself.
 
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