Hi, I also started noticing a lack of power after the vehicle heats up, I purchased a bottle catalytic converter fuel treatment stuff... had good reviews, hasn't arrived yet though.
But if I don't start noticing a difference, I'm probably going to gut them as I don't have emissions where I am.
Love your build by the way, did you get aftermarket UCA's to go with you lift?
Just bought adjustable shackles.