Update:
Replaced the following over the past 2 days:
- fuel filter/regulator
- 2 precat oxygen sensors
- spark plugs
Tested car on scanner in between each change.
- Old fuel filter was full of the typical black crud coming out of the inlet, so it was due to be replaced anyway. Fuel pressure after filter change has dropped to around 47 psi at idle, I assume I can attribute this to the new filter having more free flow.
- Not sure oxygen sensors were ever replaced, so cross that off the list.
- Lastly, spark plugs were pretty bad as well. Replaced them.
After spark plug change, Bank 1 and Bank 2 STFT are closer together. Not much delta.
What I am seeing on the scans is somewhat the same as last time.
STFT starts out high (15+) and creeps down low over time (-15+). When driving STFT is above 0 and very high. When idling, it goes negative. And if you sit for idle long enough it will continue to creep down negatively.
So I am still getting STFT too high/low, out of normal range.
Post spark plugs.pdf