try checking you catalytic converter. mine became clogged and it would fall on its face a little over 2000 rpms. had no power at all after a steady cruise angie would just whine and and pound hard trying to keep up. it ended up throwing a map sensor code but that was due to the clogged cat. i gutted the cat out and it runs better than ever. i noticed this right after 2000 rpms due the the large cam in my motor. i couldnt even keep up with traffic on the highway. just my 2 cents it worked for me.