A little embarassing but is what happens when you do not have a good baseline. Have to admit the problem has been there since I bought the car about 10k milles ago. Random P017x errors, usually on for each bank.
So I bought a new Bosch MAF and maybe slowed down but did not go away. Perodically I'd check for leaks but never found and and all rubber plastic feels like new (garage kept).

Meanwhile occasionally at a stop after fully warmed up I'd see the fuel trim go bananas. Figured that was causing but why. Yesterday I started tearing into it and took a baseline that looks like this:



Note the high negative long term trims
Year old MAF

New MAF today. Note much lower long term trims. This was about an hour's drive (with stops) speeds ranging from 25 to 45 mph. Both shots taken while parked and idling, AC on.
Trouble is I just checked and there are two P017x errors "pending" though might have been while baselining. I never saw any extreeme excursions though. Guess I'll keep driving a bit and see if returm.
Thanks for all the help.

ps that is an 8" Androd tab, phone could not display enough parameters.