2001 A4 2.8 Quattro Tip. I've been having some starting issues for the past month or so and just cant figure it out. I finally got a code(P1128 Manufacture Controlled Fuel Air Meter??) this morning after starting it.

The Problems i've been having is hard starts when warm. Cold starts are ussually fine except when it is really warm outside, even then i will have to crank it 5-10 times before firing up and when it does fire up the rpm's rise abnormally slow then idles out fine after a few seconds. Also, if i let sit less than 5-10 minutes after running it starts up with no problem at all. If i try to start it after 5-10 minutes it really sounds like bad missfires and i have to let sit for another 5-10 minutes before attempting to start again or it just sounds horrible like there is too much gas in the cylinders.

I did take some steps to fix the issue like new plugs and i cleaned the MAF. I looked around on the forums and found that people are pointing at O2 sensor and MAF which are rather expensive fixes so any advice would be helpful.