And now for the BS.... Tried to take the car for a spin and the gas pedal seemed worthless, the car idles up n down from 1000 to 250 and wants to die. I had cold engine hesitation before but sea foam patched it for a quick fix. I finally got a CEL but Im thinkin it is a O2 or cat code. I am hoping to scan in the next day or 2. This maybe a previous problem coming to life or a header install problem. Perhaps an exhaust leak in/ or betwwen the flanges?? But heres my question- if the leak is after the 1st O2 shouldn t there be no stalling/severe hesitation. Trouble shooters n opinions r welcome