alright guys first off this is my first post and i’m new here, glad i found a forum that people still uses/post on. anyways i just bought a 07.5 GMC Sierra LMM 87k original miles. the guy i bought the truck from had the EFI live 5 positioning switch put on it (no idea what exact tune which aggravates the hell outta me) S&B cold air intake, down pipe, DPF delete, 5in straight pipe. my questions when going down the road or like getting on the interstate you throw the fuel to it on tune 1 the break and abs light will come on? second question the guy said the EGR was deleted but i got to looking earlier and i can’t see any block off plates that being said if i order a EGR delete kit which kit do i need and will it have to be retuned? third question when it’s setting and idling i hear like this not really a knock but more like a exhausting leak coming from the driver side, did these have problems with the manifolds on them? or is it even a exhausting leak?