My PLX wideband is reading unusually high (15:1 to 16:1 AFR) when running in closed loop. I suspect my narrowband is fouled or failing as it is fairly old and the wideband new. The wideband AFR WOT reading matches the values from the engine builder dyno runs, which makes it look like the wideband is OK. Here is a datalog where the narrowband voltage is oscillating as expected, but it seems slow at about 1 cycle per second. Can someone post a datalog of a known good narrowband voltage plot in closed loop, so it can be compared. Thanks.

https://www.flickr.com/photos/17024232@N00/14047762660/