I have 2015 Mustang GT Procharged and have tracked it 8 times. I understand OEM cats can be a problem with Prochargers. I have tracked the car at only about a 6/7 (out of 10) and a few weeks ago finally ran a hot lap in 90 degree weather. The Cylinder Head Temp spiked to 250, I then ran a cool lap and pitted. The check engine light was on it showed some misfires and a P0358 but no P0420 or P0430 codes. My mechanic looked at the Cat and found a few hairline cracks in honeycomb but no melting and we could see through the Cat with a light. I also did a temperature check on the cats, upstream temp was 500 degrees and downstream was 590 degrees. Per AI and another muffler shop the downstream temps (outlet) should be hotter than upstream if the cats are still efficient. Not ready to add headers yet. Should I retire the car from the track or just daily with an occasional hard pull. Any thoughts are appreciated.
