Air/fuel readings and Lambda after modding

Hello friends,

i recently installed an Airaid CAI on my Automatic Mustang GT with quad exhausts, my tuner sent me a revised Version of the mod (german Tuner, but with a very good Reputation). I noticed that afterwards the A/F Ratio would be at 14.00-14.1 at idle, and the Lambda would read 0,86-0,88 at idle, couldnt really go WOT curently on account of the bad weather, but that seems to be a Little off? Cylinder head temp was staying perfectly well at 95° Celsius.
I only pump "Aral ultimate 102", ist supposed to be high Quality stuff.
I did notice that the Lambda would fluctuate heavily from 0,84-1,34 in various siutations, allthough im not sure if that is important as the drinving conditions would vary heavily. The driving, Startup and idling is very smooth, no lag no stutter.

Any comments would be much appreciated, i will try to do a WOT pull later, should one do it in a certain gear?

Thanks for your help

Don't trust the A/F on the car computer use the short term fuel readings from the logs. As far as lamba, at idle i believe it should be 1.00 with 93 octane. 0.83 0.84 with WOT. What type of fuel are you running? More the alcohol level less the lambda at idle.

thank you, i thought 1 at idle as well. The stuff is called "aral ultimate 102"
Its without Sulfur, no bio-Ethanol but bio-ether, the Octane Rating (ROZ) is supposed to be at least 102.