Im just getting into tuning my 2008 EVO X using the COBB AP. I recently drove to a lower elevation from 5,000 ft to 1,500ft. When I arrived at the lower elevation I noticed the idle pulsing badly and thought a few times it may stall, I am using the AEM stage 2 map for ACN 91 Octane. When I arrived back at my regular elevation I am still noticing the idle pulsing. So I was wondering if this is from not adjusting to the different elevations? I am thinking of putting back to stock to determine if there is something else causing this. Any help would be appreciated. Thanks!

 

I had the same issue with mine on a 2011 GSR I found running reg 91 maps or even 93 ACN helped with that but all in all I would say get a protune those of the shelf maps have bugs.

 

I had the same issue when I went from 1450 ft to 4336 ft on a spirited day of driving around the mountain. I switched the maps out and it helped some but it completely went away when I replaced my fuel pump relay because it was bad and I slapped on the ETS intake with the stage two map and everything was fine afterwards.

 

I believe a lot of EVO X owners experience the idle surge, even on unmodified ones. When I first got my evo, bone stock it had idle surge, it was random too, didn't matter what the temp was outside or if it was hot or cold. After I modded it and flashed COBB maps onto it, it actually helped a lot, but I still get the surge every once in awhile.

 

Thanks for all of the input! I am communicating with Ian from COBB, he wanted the map#. Since I posted this, I drove down to that lower elevation again and the idle began to pulse badly again. When I got back home it got 90% better, I def agree with the stock idle issues, especially when you let off of the accelerator and random hickups here and there. But this is so bad a couple times I thought it might stall out, pulsing always at idle. I actually purchased the car at the lower elevation and didnt notice any idle issues prior to the COBB tune. I am going to try a different map next time I head down there again, as well as trying to map it at that elevation. As far as I understand, using a map that is not ACN would possibly damage the vehicle since I am in AZ with the crappy gas. I will def let you know what I find out from Ian at COBB.

Thanks again.