i just spent the last 7 hours trying to figure out what is freaken wrong with my 7. i am pretty sure it's something to do with my vac line job. well the car idles fairly fine but when i give it gas (even in neutral), the car hesitate and rpm drops when i get to mid 2000. no boost. vac is just fine at idle.

i checked all vac lines and electrical, all seems fine. but still i cannot figure out what is wrong?!!?!? can someone please help.

 

Check to see if you have any CEL (check engine lights) that you may not know about. This sounds a lot like a "limp mode" situation.

There are some criticial solenoids/lines that are under the UIM that might have been overlooked, such as OMP lines, FPR, etc., which could possibly cause a situation like this.