18:15 AFR at WOT

redline10000 · 07-06-2014, 10:20 PM

Hi guys,

I just got an aam midpipe and axleback exhaust and I love it. The car feels more powerful but my gas mileage has gone to hell. Before the exhaust I could easily get 18 to 23+ mpg now I can barely get 13. I used the torqe app to datalog my afr and it says im at 18.8 afr (the commanded afr). I looked it up and this is supposed to be really lean and the car should feel like crap but it doesn't, just bad gas mileage, really bad. Am I really running lean or do I have bad o2 sensors? I dont know what else to look at to diagnose the problem so any help would be great. Thanks.

Also I noticed that my fuel gauge is going crazy. After my autox event I drove home on a little more than 1/4 tank and after about 30 miles the car went down to 1 dot and low fuel light came on. I filled the car up with 14 gallons and the gas started coming out of the filler cap. Kinda weird for that to happen when the car takes 19 gal and I only put in 14gal.

07-06-2014, 10:20 PM	#1 (permalink)
redline10000 Enthusiast Member Join Date: Nov 2012 Location: boston Posts: 265 Drives: 2011 370z sport Rep Power: 12	18.8 AFR at WOT Hi guys, I just got an aam midpipe and axleback exhaust and I love it. The car feels more powerful but my gas mileage has gone to hell. Before the exhaust I could easily get 18 to 23+ mpg now I can barely get 13. I used the torqe app to datalog my afr and it says im at 18.8 afr (the commanded afr). I looked it up and this is supposed to be really lean and the car should feel like crap but it doesn't, just bad gas mileage, really bad. Am I really running lean or do I have bad o2 sensors? I dont know what else to look at to diagnose the problem so any help would be great. Thanks. Also I noticed that my fuel gauge is going crazy. After my autox event I drove home on a little more than 1/4 tank and after about 30 miles the car went down to 1 dot and low fuel light came on. I filled the car up with 14 gallons and the gas started coming out of the filler cap. Kinda weird for that to happen when the car takes 19 gal and I only put in 14gal. __________________ AAM Axleback + AAM Midpipe \| K&N Drop in filters \| Eibach Front Sway bar \|Whiteline diff bushing\| Dunlop ZII Last edited by redline10000; 07-07-2014 at 11:07 AM.