I wasn't sure if I should put this in the EMS forum or here, but whatever... I've been running on Jeff's latest base maps for nearly a month now with a new AEM intake and a midpipe. The car drives pretty bleh on the base maps, so I've been eagerly waiting for updated maps. In the meantime though I have noticed one rather odd thing. When I come to an abrupt stop, at a light or stop sign etc the car stutters and my AFRs lean out to 16.5 or higher before they stabilize and go to my normal idle of 15. Regular idle is fine, my MAF readings look normal, and besides the excess fuel the map is using I'm not seeing any other problems, but it got me thinking what could possibly be causing this? Any ideas?

 

because the map Jeff provided is not a performance map...if it bothers you I would uninstall the AP untill Jeff gets you your next calibration or final performance tune

 

I am on a "performance" tune from Jeff I have felt this stutter also.

My AFR taps 15.5 and the car stutters, very lightly but definitely not there before, then they go down to 14.7-15 and it idles fine for a minute or so and the process repeats.

Hm

 

Well my problem with that is two-fold. Because of the AEM intake and the midpipe the stock map doesn't really know what to do with it all anyway. The car was not running well on the previous map either. The second issue is I have never ever received a "next" calibration. In the entire time I've had the AP I've only had base maps. My first data logs when I purchased it were submitted and nearly 3 months went by before I decided that I would just get the base FI maps and go turbo before I would ever get the NA maps. I finally got the base FI maps, then all the base maps were changed. I swapped to the new base maps, immediately data logged because my NA setup was all jacked up due to the AEM intake. Those logs were submitted January 6th. I'm waiting patiently, but I'm getting 14 MPG and the car runs like poo. Also because I'm running with a midpipe and I'm so rich under load, cars behind me suffer a bit.

Anyway, none of that is really pertinent to the original question. I'm going to try uninstalling and see if my AFRs are at least better on the OEM map even if it doesn't know what to make of the AEM intake.

 

When you let off the throttle it always leans out.

Do you have any screens in your MAF tube.

One screen may solve your problem.

 

It isn't the same thing at all as pegging lean when I go off throttle... it's a stumble in the idle when I stop the car. I have two screens in my AEM intake, but my idle is otherwise perfect, so I don't know that I want to remove one to try and fix this other issue.