Sounds like engine rattle between 2000 & 3400 rpm

I own a 2002 P5 automatic, all regular maintenance schedules have been done. Installed a custom intake, everything else is stock. My problem is the lugging in 2nd gear or between 2000 and 3400 rpm. It almost sounds like engin knocking. It has been getting very noisy lately. Has anyone had this problem yet? I took it to the dealer 1 month ago and they said it was my heat shield around the cat under the car ??? They took the shield right off and it cured the rattle but now there is this crappy noise. Any help would be wonderful...


Thanks in advance,

Slim

Groundlevel Customs

I've got a rattle noise only @ 3100 through 3300 rpms. And I only hear it in 2nd gear but, I have a manual tranny.

1st do you hear it in the motor?? Or under the car somewhere?? Need some details.

Okay, about a month back I first heard some rattle under the car, took it to the dealer and they ripped off the heat shield because it was loose. Now I have this engine rattle, but almost seems like knocking.