This relates to a 2003 Mustang GT, no major mods, just a standard stock '03 GT. Also, I apologize for the long post but I feel like context is needed.
I will preface this to show how I got to where I am:
Back in 2017/2018 my fuel tank was rusted and causing a leak. I replaced the tank, moved...
I bought this car with all the go-fast parts installed by a shop from the previous owner in Pennsylvania. When I bought it, it ran great with no idle or other misfire or rough idle issues. I moved back home to California and needed the car to pass smog certifications. I had to do the...