I have a 2003 LS wi BEGi S3 Intercooler two with Xede, LC1 wideband and I have been using "dyno-scan for windows" software by Auterra which allows you to track and record live data including load you may want to give it a try I think it was $230 and is also an OBDII code reader. It has been a extremely helpfull for me.

 

OK good and bad,
Found a small tiny leak, right at the intake manifold, nothing else, went ahead and tighened eveything else up an exra twse while I was at it.

Blew some air into the MAF to clear any dust.

Car didnt start, (opps forgot to reconnect the MAF)

Ran it around the block and the AFR is a little rich but about normal from what Im used to.

So can this tiny leak cause such a bad problem?

Another thing that I noticed is that my Recirculation valve doesn't seem to hold any air back, I had to plug it while doing the test to prevent loosing all my pressure. What is the normal good operation of this and how do I test it?

 

FWIW: If you are using an air filter that requires oiling like a K&N or anything that's not paper, the oil from the filter WILL get on the MAF sensor and mess up it's reading big time. Sounds like that's exactly what's happening to you. Go to Autozone and buy some MAF sensor cleaner and clean it. Then drive it and see if it's perfect and goes back to crap in a week.

 

This may sound stupid but I washed my K&N filter a few months ago to get all the oil out. I didnt care for the mess it was making and didnt think that the oil was necessary for safe operation.