[mlarco52]

I had my exhaust guy remove the resonator and it sounded great but there was too much flow causing the exhaust valves to rattle. He then put a hook on both the valves that left them open for a couple of days to see how it ran, well my MPG cut in half, and I had lost a lot of low end power, felt like a complete slug. Not worth it at all! So I went back they made the valves go back to normal and put the resonator back in place, all is well now getting normal MPG and great off the line acceleration and low end TQ once again.

Do not have your shop keep the valves open as you will eat a lot more gas and lose a lot of low end!

(I realize I already posted this in another thread, however, not everyone will see that and this will be more effective)

Edited with the new MPG! Lol.

 

[Rambit]

Thanks! I moved this into the WK2 Intake/Exhaust forum BTW.

Here's the background information on the active exhaust system.

6.4L ACTIVE EXHAUST VALVE

The Active Exhaust Valves (AEV) are located at the cold end of the exhaust pipe before the muffler, after the catalytic converters. The pressure created by the engine allows the valve to over come the spring tension and open for optimal engine performance. When the valve is closed. The back pressure created in the exhaust system assist in engine performance by:

• Increasing the fuel economy due to the increased use of MDS
• Increased use of the MDS from the AEV improvement
• No loss of vehicle performance
• Emissions remain the same.
• The AEV is welded into the cold end of the exhaust pipe. If replacement of the valve is required. The exhaust pipe must be replaced. The AEV is non repairable.

Bernie

 

[higshemi]

Wow... thanks for the heads up... Sorry you had to find out the hard way.

 

[Jack_Toepfer]

MPG Doubled?

You mean it went from 15 to 7 and not 15 to 30 right? Otherwise, that wouldn't be a bad thing... (other than loss of power)

 

[Rambit]

I'm sure he meant halved or that consumption doubled.

Bernie

 

[mlarco52]

Thanks Bernie.

 

[mlarco52]

Yes well I'm in Canada and I have L/100km and it went from roughly 19L/100km to about 35.

 

[5000XD]

That's the love hate relationship with backpressure. Now with a tune this would be a different story!

Thank you for sharing your story.

 

[BOYCHIKS]

Nice feedback. I know this was brought up before they hit the dealers, as they mentioned the technology that went into the exhaust and how it may be the best for the '12.

 

[MJC]

This truck is gonna be such a headache to modders. We're just scratching the tip of the iceberg here.

 

[KINGMONKEY]

I left them in and cut the resonator I'm good but glad to know