Lack of power and a 'grumble' when putting foot down
 

I am going to try to explain this as best I can. It's most likely going to sound like a vacuum leak problem, but I want some other input.

I bought my 2002 Audi A4 B6 1.8T Quattro about a year ago with 95,000 miles. When I bought it it seemed very light and agile and the engine was very responsive. 4 or 5 months after buying it and replacing the crank case breather hose, suction pump and the main vacuum lines to the Kombi valve and the solenoids under the intake manifold, I noticed that sometimes the car would have that light, agile engine feel to it and then others it would be kind of grumbly and not be as responsive and feel less powerful.

The only code I am throwing is the PO4011 for the 'incorrect flow detected' for the SAI system. I am starting to conclude my SAI pump is not working. I did have water in the bottom hose before I replaced the Kombi valve (which was bad) and I don't hear it upon a cold start. The only part of that system I haven't thoroughly checked is the plastic intake/outtake hoses, which if there were holes in either of them it would most likely throw the code.

Now, when I start my car it has a bit of a rough idle and is kind of rumbly. In most cases if I turn of the car, wait a second, then start it back up it runs much more smoothly. Still it lacks the original power and engine responsiveness that it had before.

The engine just seems to be bogged down and I can feel the vibration/grumble in the gas pedal when I accelerate.

Does this sound crazy?