LT1 problems

Hi. I'm a carguy from Norway.
Is there anyone who can help me with a problem I have on a 95 LT1.
I use PSI wiring for this setup.
I was driving and suddently it started to run very rough with load. It seemed like it only ran on 5 or 6 cylinders. I looked at the spark plugs, and 2 on each side were almost white and the other two was really black. I changed the spark plugs and the problem seemed solved, but I still have a little rough idle. Then I hooked TunerPro up to see I could see any problems. I found that both the O2 sensors is jumping up and down all the time. I changed the sensors but it's still the same.
I have attached a log-file.
Any ideas about what this could be??

Quote:

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I found that both the O2 sensors is jumping up and down all the time.

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the o2s are supposed to do that. narrowband o2s only really read 'rich' or 'lean', so the ecm needs to go rich,lean,rich,lean really quickly to get a good average mixture. when your o2s are 'switching' back and forth rapidly, that means the ecm is near its target air fuel ratio, and that's generally a good thing.

it seems they're compensating for a slight lean condition and adding fuel. if you look at the 'blm' values you will see how much of an adjustment is happening (as a difference from 128 being ideal, higher being fuel added, lower being fuel subtracted)

this may not be an actual lean condition, but a misfire on a few cylinders (a misfire tends to read as lean to an o2 sensor, as it just pumps oxygen into the exhaust).

i'd be looking for burned plug wires or similar per-cylinder issues