I recently put o2 sensors in my Dana Exhaust to monitor A/F. I have a pretty good split between left and right. I set the Port side to be about 12.7 or so at the leanest point. When checking the otherside, same day, nothing changed it was up 13.5-14.0 all the way thru the rpm range.

I've been working with Raylar on the problem, his suggestion was a possible exhaust leak or bad or clogged injector.

I'm going to check both those things, just wanted some other possibilities or maybe some similar situations from other people. Once I dig in there I want to check everything.

496 HO, Raylar cam, Dana Exh.

Thanks in advance-

Anyone?

You may also want to check the spark plugs one slightly fouled will cause a change comparing side to side. Another possibility is the wiring of the O2's if you have a extra long circuit conneting to one side compared to the other this will add some additional resistence and could cause a minor shift in your readings. If you have more splices or terminal connections on one side compared to the other you may also see a slight difference in the readings. Maybe try swapping the O2's and see if the readings swap sides or if they still read the same. I think the exhaust leak would be obvious and easy to see if that was the case. Injectors not so easy.

Launchpad475, I'll keep you informed on what we find. We are soon to test both banks of a 496HO with widebands for CMD Marine testing data.

Cool thanks. I put an o2 sensor on each side instead swapping back and forth. Now I can watch them together at the same time. Still working on it. Split seems better though.

Turns out I just had a bad connection on one side, swapped o2 sensors around and swapped cables back and forth and was able to get consistent readings within the range I wanted.

Glad I could help. I'll send you the bill latter