As ZRAY say's ltft+stft should be under 10.00

E.g ......Bank 1 stft +0.8 ltft +17.2 = 18.0
............ Bank 2 stft -0.8 ltft +18.0 = 17.2

If a bank get's to 25.0 (two times) you will get a confirmed code and engine light on the dash.

 

Thanks for everyone's input..I have a couple more questions now..I still have potential fuel pump issues in my head..I checked the pump PSI at idle in park on both pumps, and had 40 on the primary and 38 on the secondary. Do I need to check pump PSI under a moderate load, where the high trims show up, or is the idle check good enough to call the pumps good? I also read that if a vehicle has a MAP sensor, which I believe my car does, vacuum leaks will have no effect on fuel trims? Not sure if that is correct. Would the fuel trim levels I have cause performance issues when driving or is the compensation adequate to keep engine performing correctly, unless the trim gets high enough to trip a code? Seems to me there are all kinds of potential problem areas..from a troubleshooting standpoint, where is a logical place to start?

 

It would not harm to check the fuel psi under load, Then you can rule the fuel pressure out, Don't think at a steady 2400 rpm you would have both pumps kick in so if you do this test i would check it with WOT also this should have both pumps running.

Yes vacuum leaks WILL have an effect on the fuel trims.
I don't think your high fuel trim's will have that much if any effect on the car's performance, But it will have an effect on your mpg.

Logical place to start troubleshooting.............as you say "there are all kinds of potential problem areas"

From my understanding the classic air leak symptom on fuel trims is that they are high at idle and as you increase the rpm they come down.
From my understanding the classic fuel delivery problem symptom on fuel trims is that they are low at idle and as you increase the rpm they go up.
This is just my understanding and there will know doubt be the exception to the rule which could contradict the above, hopefully some one can explain them.

Your fuel trims are much the same on both banks which can rule some things out as it's doubtful that the same things on each bank would fail at the same time to cause the ecm to add the same extra fuel to both banks.

Ok it's either ....1..unmetered air entering both banks equally or...2..a fuelling problem effecting both banks equally.

Could it be a dirty maf or a bad maf that under reports the air to the ecm ?
Could it be failing fuel pump's or a small fuel restriction / blockage ?
Would a dirty throttle body cause a fuelling problem ?
Also to keep in mind is you think the car is sluggish ....
Hope this helps ......Could be worth starting a new thread on your "fuel trim's and likely causes" might get more people responding.

 

XKR-DAY,
Thanks for your input...I'll start from the top with the MAF sensor..My scan tool reads pounds per minute..Any Idea what correct reading for the SC engine is and at what RPM's? I located the data for the NA engine in multiple areas, but not the SC engine.