Well, we're talking 4.0's. Even if it did/does default to 14.7, then it shouldn't show 16.x at wot.

 

it might still be crude enough to go into open loop WOT even though it’s got a wideband.

didn’t the other cars you try sit in the 14s? i can try to see with an IDS if it reports accurate data, 16 afr at WOT makes no sense.

https://www.jaguarforums.com/forum/x...an-wot-243521/

 

I haven't trusted wideband readings for a while not in my job. Just because I don't trust them readings from the tester point of view. This is why sensor after cat is great sensor to read. My xjr now after maf replace gives 0.8-0.9V from both downstream sensors @ wot. 0.8-0.9V is spot on mixture for wot. And that is not 16.x. It is somewhere 12-13afr.

 

Neither does 14.7. Or 14.X.

This is why I like MAP based AFR and not MAF. MAP sensors rarely fail too. MAF on the otherhand...How the air hits the sensor can throw it way off.
My Softail's AFR is what I put in the table with my race tuner based on MAP, throttle position, and rpm. Same with ignition timing. The VE has to be dialed in of course.
Quite frankly, I don't trust the stock MAF sensor with anything but the stock airbox/intake and who wants that restrictive thing. At least it sucks cold air tho. Just not much of it. Good for low end power. Not so good for higher RPM much above 3000 or so.

 

The last 02 xjr I scanned, were in the 16.x wot afr.

I will into buying an IDS. I did use an Autel or Solus(I think) and it was able to read all codes. But, the only thing it didn't show were AFR'S.