I noticed today after doing a log that my idle afr's are quite lean, around 17:1... The car runs fine and idles fine the afr's were just worrying me.
The strange thing is that as soon as I start driving the ratios return to their normal 14.7 range in closed loop and in open loop they are around 12.5 exactly what i have it tuned for.
Anyone have any ideas? could my first oxygen sensor need replacement. My idle afr's used to be right at the 14.5-14.9 range. I reset the computer but it didnt change anything, could it be a vacuum leak?

 

I don't think it could be a vacume leak since your open loop is fine.
Since you have Emanage try adding some fuel to idle.

 

i tried to add fuel at idle but, it seemed to just readjust my settings. It is as if my ecu thinks 17:1 afr is stoic.

 

my car idles around there as well...always has. it is never an issue though. once you apply some throttle it returns to a burn much closer to stoich (14:1 - 15:3) when you are just cruising around. open throttle it returns to 12:1 - 13:1 (and i pray to god i don't start knocking when that 13 shows up at open throttle). like greg said though. try playing with emanage a little more. there should be a way to over-ride its 'auto' setting that keeps changing what you set it too.

 

^Why are you afraid of that 13?

 

I just bought a OBD scanner so I am going to check the codes my cars is pulling.. If it is still only the catalytic converter code I am not going to worry about it.

 

never mind.. thanks for the help. I found an exhaust leak today which was causing the lean idle readings.

 

i read that the car starts knocking around 13:1...it could have been inaccurate though.