Having code P0171 and hesitation at acceleration

Recently replaced timing belt and water pump. Set timing with slot tool and bolt in block. Runs good at idle normal rpm. I would expect high idle and racing if it had a vacuum leak. Ran good before belt change. I could not find any information on what position the VVT should be in when setting the timing. I suspect that it is a slight timing issue due to the VVT, but I would think it wouldn’t run if timing were off by even a little bit. If I unplug the MAF it still runs okay but sometimes will shut off when unplugged. Recap: don’t suspect vacuum leak. Fuel pressure 35 to 40 psi constant. Somewhat suspect MAF. Mostly suspect VVT. What do you think?