We have a 2007 F350 6.0 with egr delete and sct tuner. My husband switched the tuner to stock mode and the check engine light came on after a couple days of driving, with a code of p0401 egr flow restriction. Is that because he put it back in stock mode? Can we clear the code?

 

1) Yes because the custom tuning will work around the CEL. When back to stock it sees the low flow.
2) No the code will continue to pop up after clearing.

You need to load a tuning file to prevent the CEL. Driving on the CEL should not cause any issues.

 

If you have an EGR delete the SCT is supposed to be the only or one of the few tuners that can clear the code and keep it gone but the only way to keep it gone I believe is to have the ERG parameter set OFF. I'm trying to remember this off the top of my head but I dont think you can set just it off and leave it stock. When I had my EGR deleted the guy left the valve in place but it was bypassed. leaving the valve on fools the computer into thinking its still there so the check engine light doesn't come on. Then once I bought my SCT I keep it tuned and the EGR off.

 

Just make sure you have to egr turned off on your sct programmer, if not you will throw a code everytime.