RockStang

I think it's close to 14 or a little above.

jpplaw

I did not know that stock 2013's were coming with wideband AFR gauges.

During idle and cruising (closed loop operation), air fuel ratios (AFR) will always fluctuate. It will never be steady.The ECU, with the help of the O2 sensors, is always trying to keep the ratio at 14.7 to 1. So the ECU is constantly adding or removing fuel. At start up for around 30 seconds or so, and at WOT, the system goes into open loop operation. This is a default AFR setting in the ECU, with with no aftermarket tune, this is usually 11 to 1.

A reading of 20 to 1 is dangerously lean and usually means a massive air/vaccuum leak.

What is the ratio range when cruising? At WOT?

RockStang

I only get 20 when I completely let off the throttle, during normal driving the af ratio is just under or just over 14

RockStang

I would have to go for a little ride to let you know the true afr, I'll be back very shortly to let you know.

jpplaw

Sometimes you can get a spike when you let off the throttle, but thats usually 15.x - 17 max. Nothing to really worry about. As long as when you are cruising the AFR is in the vicinity of 13 -15 and WOT is less than 13 (ideally around 12-12.5), you are ok.

RockStang

Ok, just fueled up with 91 octane (shell) idle is at 14.0, WOT is at 12.1 and normal driving is around 14.0

RockStang

Just before shifting on wot it goes up to 20 but after it stays at 12.1

RockStang

Great!! Thank you very much for helping me Sir!

I Greatly appreciate it