I have a b20vtec tuned on a pherable ecu, the car was tuned and we used a wideband. I just recently Installed a AEM wideband gauge in my car and under WOT its okay like 10.8- 13.5AFR depending on load and rpm but idle still is 14.5 AFR. When I'm cruising around 55-60 and I hardly have my foot on the gas maybe 10-15% throttle it reads 16.5AFR should I be worried? I haven't checked plugs but car seems to run top and doesn't miss a beat

 

NOPE. Let it go. If the car isn't "bucking" while you are cruising... you have nothing to worry about.