Atlas 40 FICM Tune

[jmj12396]

I had Ed at FICMrepair.com fix my FICM and put the Atlas 40 tune on it. My truck is stock other than straight 4" exhaust and blue spring fuel pressure upgrade. Ed did a great job and I've gained 2-2.5 mpg. I wanted to ask you guys that also have the Atlas 40 tune if it changed the way your exhaust sounds--especially right after cranking. After starting my truck the exhaust sounds normal for a few seconds, then it sounds like someone put a bucket over my tailpipe for about a second and then it alternates between sounding normal and sounding muffled a few times. Is this something the Atlas 40 is causing? I never noticed it before I fixed and tuned my FICM.

[russ_]

Were you up to date on your ECM strategy (VXCF9N4) before the FICM tune? Mine started sounding exactly like what you are describing after it got updated. I believe it is the vanes on the turbo cycling to help prevent sticking at idle.

[jmj12396]

I had my ECM flashed at the Ford dealership in 2008 or 2009 in order to get the inductive heating strategy try to help my cold start issues. It hasn't been flashed since. From what I understand, the Atlas 40 tune changes the way the inductive heating works causing the injectors to heat in sequence instead of all at the same time to decreased the power drain and the strain on the FICM.

So, is this sound normal? Should I have the ECM flashed? I plan to do an EGR delete soon and don't want to have to buy a tuner, so I'd rather not get the flash that sets the check engine light.

[russ_]

My truck has sounded that way for about two years now. I'm guessing it's fine.