65mm throttle body in but a/f ratios ok?

[RedNightmare06]

I installed a 65mm ford racing throttle body. When I take it for a ride and watch the stock a/f meter it seems to be back and forth. When I punch it I get 11.8 to 12.8 and if I come off the gas pedal it seems to shoot up to 16 to 19. Looks ok with normal driving running 13.8 to 14.5. Along with the 65mm tb I have a air raid filter, frpp resonator delete and corsa axel back. Stock tune. Is the stock a/f meter accurate? Do I need a flash tuner? Thoughts?

That's sounds pretty normal it will do it with the stock TB too , You probably never noticed it. The stock A/F guage is real accurate , it getting the reading from the wide band 02's in the exhaust pipe.
The reason why the a/f shoots up is called coasting fuel. The ECU shuts off the injector while coasting . The a/f gauge can go as high as 20 when in this state . It's for gas mileage and emissions.

If the car was to lean yes it would pop a code , it would also pop a code if it was to rich too

 

[13 Cobra Toy]

Put the 65mm throttle body on the car and enjoy. I have 1K street and 300 Hard open track miles. No hard faults or lean counters and still have my factory warranty intact.