Fuel trim codes and S2 O2 sensor codes

[toolman617]

I'm thinking they may be related, but here's the deal. Last weekend I replaced all 4 O2 sensors (I know, prolly didn't have to, but figured I'd do them all while I was at it, $50/ea on Rock Auto), the spark plugs, and cleaned the MAF (used MAF cleaner spray). Right away I got B1 S2 and B2 S2 O2 sensor codes, slow to respond, intermittent - 16523 and 16543. Today it threw 17535 and 17537 - fuel trim B1 and B2 system too rich. It was running horrendously. I cleared the codes (thus resetting the fuel trim data, I found out), and then logged. I know that I have boost leaks, so the boost measured reads less than requested under load. Few odd things - I read Ross-Tech's white paper on MAF issues, and the scenario I have doesn't fit either of theirs. Mine is the opposite of a MAF going out - normal additive, out of spec negative multiplicative. Other thing (which I noticed in the log and didn't do any reading on) is the engine load - it was peaking around 160%. I would think engine load is tied to throttle position, but either I'm wrong or something is wrong there. Other thing was the multiplicative fuel trim. Under heavy throttle it would go to 0 (can see this in the log), less throttle it would go back to -4.7. Not sure if this is normal or not. I did peruse the engine bay, and I don't see any hoses that are loose or degraded to the point of leaking.

On the O2 sensors, I don't have any exhaust leaks that I can hear. I was thinking about trying find some O2 sensor safe contact goo (whatever it's called to promote electrical contacts) and put some on the rear sensor connectors. Just seems weird that both rear sensors would have the same problem, and the fronts are fine.

So, any thoughts on these codes? Related? More things to measure, take a look at?

Log file (https://onedrive.live.com/redir?resid=2E818D5E1113A8AC!8803&authkey=!AKRkWdTu6Ltp03s&ithint=file%2c.CSV)

[toolman617]

Some more data. MAF readings, from what I can tell, are in spec, which I found as "Specified is 1.8-4.0 g/s at idle and @2520RPM spec is 7.5-12.0 g/s" in a post on another forum. However, after driving for another day, the additive/idle trim is 2.3%, and the multiplicative/partial fuel trim is at -23.4%, which is obviously waaay outside of spec for partial.

Also looked at blocks 001 and 031. Lambda controls (block 001) were down to -14% at 2000rpm's stationary, and up to 14% at idle for both banks. Sensor voltage (031) varied a lot - specified voltage was 0.435V, and it ranged from 0.085Vish to 0.9Vish. Should it normally vary this much within a few seconds at idle?

Obviously I've been trolling many threads here on many different forums. Anyone have any other input, ideas, things to look at or try? I'm about out of things here.

[toolman617]

Thanks for all the help guys!

For anyone in the future that has this issue, it was my throttle body boot. Popped off, and once I put that back on, all the codes went away and fuel trim is normal again.