what would cause it

How lean? Could be fuel pump/filter/injectors just not pushing enough fuel. Could be MAF or 02 sensors, but that would usually cause the car to run rich. ...Maybe a vacuum leak.<ul><li><a href="http://www.ttguy.com/html/maf-vag-com.html">This article may help a bit too...</a></li></ul>

ok,here is my question, i have been under the hood and looked around, but i have never had a audi for 1 or a turbo car for 2 so the way things are set up are a lil different from my 4.3 v6 s-10 my sonata or my 2.0 cabrio, my most recent/present cars

could someone that is familiar with the motor look under the hood and see if there is a hose not connected or something

i live in des peres

cell # 314-302-7515

Chances are, you wont be able to see an obvious flaw in the line. You will need to test the pressure on the vacuum line. However, I did find an article (posted below) from a guy who did. Seems to be a common problem.

How did you find out it was running lean? Are you using a Vag-COM?<ul><li><a href="http://forums.audiworld.com/a4/msgs/1521426.phtml">http://forums.audiworld.com/a4/msgs/1521426.phtml</a></li></ul>

check engine light took it and got it tested

what is vag-com, i am new to these rides

also i never loose power, it acts the same, got all the power of 190hp

A Vag-com is basically a code reader. You plug it into your car and into your notebook and it spits out error codes and does some real-time monitoring. I have one, so if you want, call me and I can take a look at it. 618-696-2302.
Matt

isolated to that bank. For engines with one bank (4 cylinders) it leaves pretty much everything open for suspicion. Possible causes that I'd check.....

Intake manifold leak (at head), exhaust leak on that side, bad spark plugs, clogged injectors, clogged exhaust on that side, burnt valves, bad valve springs, cam chain tensioner failed....

4 cylinder specific: L hose under coolant reservoir, check valve at the top of air filter assembly(check valve for evap purge valve), vacuum lines, bypass valve.

Check block 32 with vag-com &amp; post your findings. I can talk you through from there if you need additional help.