STFT should react quickly. LTFT reacts much, much slower.
However, if LTFT is that far out, something is badly wrong. LTFT for an Omega on petrol should never deviate from 0%
That's what I thought. I have run it for the last few days with the scan tool connected on short journeys but wormed up to temp and the LTFT never changes from 7.03. Any suggestions what graph to look at next to diagnose the problem?
Thanks
Is this for the 4 pot in your profile, or a V6. V6 makes it easier to diagnose due to 2 sets of data.
That link was misleading on page 2. On an Omega not on LPG, LTFT should *never* drift from 0% (or 127/128 on non EOBD compliant cars).
The usual reasons you have a LTFT > 0% (ie, running lean, the most common fault) is an airleak in intake systems or exhaust (particularly if pre cat), a suspect MAF, or knackered lamda.
With a V6, due to 2 banks, you can rule out MAF if its only happening on 1 bank.
Get the MAF reading. At idle, a 4 pot should be approx. 12kg/hr, a small V6 about 13kg/hr, and a proper v6 around 14kg/hr. Additionally, careful check for any unmetered air being able to get into the intake or top end of exhaust.