Quick update on the situation. When I started it up this afternoon the check engine light turned its self off. Which was nice. I kept an eye on the fuel trims, which also were doing better. Mostly keeping to about 10-15% (long term). Also heckled on the 02 sensors which were fine. The trims were also behaving like a more classic vacuum leak, higher on average when my foot was off the gas.

the other thing that was off on the live data was the STFT bank 1 sensor 2, which I think means the downstream O2 sensor was giving readings around 99%, though the voltage from all the o2 sensors was in the normal range. I’ll verify tomorrow. Does that mean it needs a new o2 sensor?

thanks again

It might.

Hard to tell with another known issue skewing things.

Can you tell if it is cycling properly?

Well, last night I spent probably half an hour smoking out the vacuum system for a leak, and found nothing. So I went back at some of the live data and freeze frame data to see if I could find anything. With the engine off MAP was the same as barometric pressure. At a cold idle the MAP was about 12inhg, which I think is plenty of vacuum, and the MAF was at 8 g/*, which I think is high, but makes sense if it’* cold maybe. At the moment the code was thrown the MAF was reading 3.4 g/*, low i think. Could it be a MAF problem maybe?

also thought that fuel injectors could be the problem I guess.

anyway hoping someone could double check my deductions here.

thank you

Need to know engine RPM with the each MAF reading. Would be helpful to know if it is open loop or closed loop also.

Took a couple more complete readings this morning.

At idle:
fuel system 1 closed
fuel system 2closed
calculated load value16.1%
coolant temp 192 degrees
STFT bank 1 -.8%
LTFT BANK 1 11.7%
STFT bank 2 -2.3%
LTFT bank 2 10.9%
Intake Manifold absolute pressure 10inhg
RPM 544
speed 0
ignition timing advance cyl 1 19.5 degrees
Air flow rate from MAF .63 lb/min

at about 45mph
fuel system 1closed
fuel system 2closed
calculated load value 42.4%
coolant temp 192 degrees
STFT bank 1 -1.6%
LTFT bank 1 12.5%
STFT Bank 2 0%
LTFT bank 2 10.2%
intake manifold absolute pressure 17inhg
RPM 1768
speed 43mph
ignition timing advance no. 1 cyl 32 degrees
intake air temp 73
air flow rate from MAF 4.29 lbs/min
absolute throttle position 18%

the long term fuel trims are definitely trending down. They are highest when coasting down hill, today about 16%, a week ago it was around 22% and lowest when accelerating today as low as 7% and a week ago around 14%.

Not sure why they would do that, and I can’t see anything else wrong in these numbers.

thank you again