Acceleration Chittering Noise?

sounds like a low octain fuel..pinging...try and add some higher octain gas and see if it goes away or gets better.

If higher octane isn't the answer, Its recommended a new timing gear, chain & guides be replaced before 150,000 for preventative maint.

I have the exact same problem. I have a mechanician checked it. He said it came from the transmission. Did you solve the problem? Any suggestion?

Had the same issue and found that the trouble code was P1405, which has to do with the EGR Valve and related systems. I found that one of the hoses on the DPFE (Delta Pressure Feedback EGR) Sensor had come off. After plugging it back in, the noise went away and I was able to clear the trouble code. The DPFE Sensor on our cars is located at the very back of the engine on the passenger side (just in front of the transmission dipstick). It has an electrical connector and two tubes (facing downward) that should have hoses attached..

I have the same chittering sound in my 07 CVPI. Mud dad also had it in his 06. In my experience, it also occurs at constant speeds but you will only hear it if you are within 3-5 feet of a wall or median or curb on the driver side which will allow the sound to reflect so that you will hear it. From what I can tell as an automotive Noise and Vibrations engineer, the sound source is your catalytic converters, the sound path is a discontinuity in your exhaust piping most likely at the exhaust/cat connection points, and in my case was due to rust damage. The reason you only tend to hear it at hard accelerations at low speeds is because all of the other sounds like wind noise and road noise at higher speeds will have a masking effect on that chittering sound. But I bet if you roll your window down and drive next to a wall you will hear it while you're next to the wall and as soon as the wall ends, so will the sound. I would recommend inspecting closely your exhaust from the headers all the way down to the end of the exhaust and look at all intersection points for any discontinuity or cracks or holes. That will show you where the sound is leaking out from.

Dude its the egr pressure sensor on top of the egr valve. They start sucking air and is precisely why you hear it during quick acceleration due to the sudden spike in engine vaccum. Also hard engine braking or closing the throttle valve abruptly at speed does this as well. This seems to be another (of many) reacurring problems with FoMoCo's 4.6L V8. Really not bad engines but if you neglect them and or dont use the recommended weight oil. They wont last long at all.