Took my car to the mechanic

[2002 v6 camaro uncharged]

I decided to finally take my car to the mechanics after over a month of trying to diagnose my problem. I decided to take it to the dealership thinking they should no more about my car than an off the wall mechanic.

They told me they were having there high performance mechanic look at and after $119.00 later I don't know much more than I did before and he said they could not find more out until the started tearing things apart.

Here is the original description of my problem.
http://www.camarov6.com/ubb/ultimate...c;f=1;t=016479

The only things the mechanic could tell my is the pressure check of the cooling system showed no leaks, he could not find any vacuum leaks, the O2 sensors are working appropriately.

So, If the vacuum is fine and the pressure check was fine does that eliminate a intake leak?.

Could a leaky EGR valve cause it to run lean in bank 1 and 2? The EGR system is one of the few things I have not checked yet because it has not thrown any codes but I am fishing here trying to figure this stupid thing out.

[2002 v6 camaro uncharged]

I forgot to also mention this. I originally said it was just running bad at idle but the mechanic said that the fuel trims were as lean as they could be and the computer is compensateing for it making it run rich at idle as well as during acceleration but not as bad as idle.

This morning I scanned my car with the MAF plugged in and watched my fuel trims, my STFTs and LTFTs were sitting at 19.5%at idle. When I started to drive the STFT were moving around the 10% range but the LTFTs were pretty much locked at 19.5%, Sometimes they went down but were mainly 19.5%. (This scan was only like 10 minutes because the computer crashed on me)

Then I scanned it with the MAF unplugged and the STFTs were going a little bit rich a little bit lean back and forth like that. My LTFTs Were moving around staying mainly lean but went rich sometimes also. This scan was for about 30 minutes and about 75% of the LTFT readiings were lean going all the way up to 26% a couple of times and the other 25% of the readings went rich as far as 22%