So i swapped my rear cats with magnaflow cats and damn the truck came to life. i have dual exhaust with a si/do flowmaster and it sounds sweet. Not as loud as i expected but the acceleration is great and constant growl on the road which makes it sound like a beast not just a drone. Just had to let everyone know that it didn't trip a code and is worth doing. 2 cats $120 shipped installed 2 hours $150 total $270