Hey I just installed Stainless power long tube headers and a gt350 intake manifold on my 15 mustang gt. I have a custom lund racing tune. Has anyone had any problems with the throttle? Cold start my rpm is super low like under 1k. And it stalls. Then while driving from dead stop the throttle is very laggy. Like kinda sluggish. This is my first tune on any car so I don't really know if this is normal. Any help would be nice thanks.