acceleration noise
 

When under light acceleration and the speed is just below 30 mph and until I hit about 40mph (1750 to 2250 rpm range), there is a very deep/low pitch noise coming from the engine. When its doing this you can also feel a vibration similar to what you feel when the bass on a stereo is set high. The car is an automatic but it feels like you are driving a manual and trying to accelerate at 30 mph but you are in 6th gear. I can't tell if it is coming from the intake? Fuel injection/fuel system not putting out enough? Or worst case something in the transmission? The vibration feels more like its coming from the engine compartment but you can feel it down the center console.

Any ideas? Thanks!!!

Any codes? Could be MAF sensor, could be tranny software. At what rpm does it finally upshift? Are you seeing the same thing in both D and DS mode?

I have experienced MAF codes before, but right now there is no SES. It finally shifts closer to 3000 rpms like normal. And this mainly happens in D, DS mode has higher rpms. It does have idle issues which I do associate with the MAF, but I didn't think the MAF would cause that kind of vibration under light acceleration. I only really notice the problem when going through residential areas and sometimes i do feel it taking off from a stop light.