2002 Passat code: P2096

P2096... post catalyst fuel trim system to lean bank 1
I have an 02' Passat GLX 4Motion Wagon 2.8L (automatic if that even matters)

I replaced all 4 O2 Sensors, and the code is still there. Replaced spark plugs, fuel cap, fuel filter, purge valve, & went through a smog test so no vacuum leaks. It has been taken to the dealership twice for tests, 1st time they told me to replace the rear O2 sensor & purge valve, so I did, and it still came on so then I said f** it I will just replace all the O2 sensors, and it's still there.. So I went back and dished out another $150 to have them test the damn thing again, I could've gotten my money back if the same codes were still there, but the other code: P0441 went away so I got f*** in the ass. I will not take my car to get tested again...
So was hoping if anyone had any ideas on what this could be?
Cat Converters? Fuel delivery problem?

The only symptoms I am experiencing are horrible gas mileage probably 13-15 mpg (I know they typically get 19-26) The check engine light is on it's been erased after putting in new parts and keeps coming on. It will stay on and go off after a week and stays off for 2-3 days then comes back on, but now it's on for 2 weeks and goes off for like a couple hours and it comes back on again. It's rather annoying and I just don't know what to do with it anymore...:runaround:

And yes I already know Volkswagen is junk, you don't have to remind me, but it's a little too late and I can't sell a car with CEL on unless I erase it on them and screw them over, but I'm not that kind of person. The dealership screwed me over and that's exactly what they did when i bought it.

How many miles on your Passat?

125,000 almost

I had the same code once on my New Beetle(82,000 miles). It cleared. Then the next day a code P1128 showed up. To make a long story short it needed a new MAF(Mass Air Flow Sensor). Problem solved. Try cleaning the sensor with MAF cleaner before you decide to buy a new one.

I don't have any symptoms of a bad MAF, my car still drives like normal.

I don't have any symptoms of a bad MAF, my car still drives like normal.
Your gas mileage is not normal. Have you ever cleaned the MAF? A MAF cleaning is considered normal maintenance. What do you have to lose! MAF cleaner is less than $10 a can.