Need sct x4 users help please.


New Member
May 10, 2020
I'm working on a 2003 4.6 Mustang GT with a p1sc and 42 lb injectors and I'm trying to get it tuned myself so it at least runs decent. I knew it needed a tune for the 42's and a local tuner said to get a SCT X4 to tune it. He wants $400 to do it but I wanted to give it a shot myself and hope for the best. I'm running a stock MAF in a bigger housing. For one thing, it only goes up to 30lb injectors? Also there's no way to tune the air/fuel? It only has WOT adjustment. Right now, the car starts and idles fine at first but when it goes into closed loop, it starts running rough and seems to hunt for a idle speed. I logged it with hp tuners and the 02's are shooting up in the 940's at idle, and that's when the problems start. Is there any way to lean it out with this tuner? I'm assuming if he was gonna dyno tune it with this that he would be able to do it. Or am I gonna have to go with 30lb injectors? Thanks for any suggestions.
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