Months back I picked up an occasional skip, then the converters started to rattle, more recently it is way down on power and has a ping,if you push it, it will drive through it and feel fine ... also begining to notice that on a steady run just below the ping it will slowly come back to life and begin running fine again and then it will fad again but you never know exactly when - granted this is also after just hollowing out both cats...... has new pulgs as well ..... any thoughts ????