Injuneer

Where do you see a lean condition? Advise scan time for the lines you feel are a problem. You are in Power Enrichment Mode from 40.83 seconds through 58.38 and the average Bank 1 O2 was 0.889 Volts, and the average Bank 2 O2 was 0.897 Volts. I'd say that's right where you want them, recognizing that stock narrow band O2 sensors are not particularly accurate at the rich levels required for strong HP and torque.

Cell 15, which was used in PE is adding 4.7% extra fuel on Bank 1 and 3.1% extra fuel on Bank 2 to prevent it from running lean. Anything within +/- 5% is actually pretty good. Why would you want a BLM locker to prevent the PCM from making that kind of adjustment? That would only make things worse.

Is it possible you are seeing the 0.004 Volt O2 sensor readings at closed throttle, and assuming that means the engine is running lean? That simply means the PCM cut off fuel flow on deceleration.

Your excessively high long term fuel trims are in the part load cells used for closed loop. Worst conditions (Cells 2 and 10) the long terms are adding 13.3% fuel on Bank 1, and 9.4% on Bank 2. Whatever is affecting the A/F ratio is slightly predominate on Bank 1. But note - THE ENGINE IS NOT RUNNING LEAN - the long term fuel corrections (BLM's) assure that. You do not want a BLM locker on a basically stock engine. You will do more harm than good. The lower the load (air flow) the higher the amount of extra fuel being added. So, you should look for a possible source of that problem.

-insure the MAF sensor is clean
-look for air bypassing the MAF sensor - cracks in the elbow, leaking throttle body gaskets
-check the EVAP system for vacuum leaks - that is running 100% open (100% duty cycle) in PE mode, and open a high percentage of the time under other driving conditions. A crack in a line way back by the canister could cause problems.
-check the usual sources of vacuum leaks
-check for leaks in the PCV system, both the air supply (TB to valve cover) and vacuum line for the PCV.
-make sure there are no exhaust leaks before the O2 sensors
-check for intake manifold leak - the on at the back of the manifold by the EGR tube

Have the injectors ever been cleaned?

When you go WOT, the ignition volts start to drop. At one point there is a single reading of 11.2 Volts, but the system seems to recover and hold 12.5 Volts after that. System voltage should not drop as RPM increases. Maybe Gary can look at that part of the log.

Gtpguy

I did a scan (not the 1 i just sent to gary )mand the leaner side was hitting 155. The scan I sent you was hitting 138? I just thought higher than 128 was lean and not good, that's my basis for saying its lean. I swapped to a new PVC and hose and scanned again, but haven't taken a look.

You saying its not lean has put me at ease, so I'll start looking for leaks in those areas. And the injectors haven't been cleaned in the 4 years I've owned it.

GaryDoug

That's apparently because the low speed fan(s) come(s) on at that time. I don't know why it does that however. I also don't see why the voltage recovers to almost 13 volts later while the fans are still running (?) unless it's because the rpm goes way down. Perhaps the alternator stops working well at high rpms due to brush hop on the slip rings.

Injuneer

The engine would be running lean if it was not for the long term fuel trims. But it would be in your interest to determine why the PCM has to add that extra fuel to keep it from running lean. The goal is to pull the BLM's down as close as possible to 128 (+/-5%). But you don't pull the BLM's down using an artificial means like a BLM locker. Done incorrectly, it would possibly run lean. You pull the BLM's back where they belong by looking for and fixing the problems that I mentioned, and probably a few others that I didn't think of.