I have a strong suspicion one or more of my cats has died. Driving home from work today I gradually lost power and the exhaust note disappeared. My wife noted that she usually can hear me pulling up to the house, but not now. Also, the vacuum line on the bottom of the EGR blew off. From what I've read on Mud, these are signs of a failed cat. It did throw a P0420 once when I was in Baja six weeks ago, but it never came back after being cleared. I know I had a crack in the crotch of the Y pipe in the exhaust header, which I had plugged with muffler putty before Baja, but it is now leaking again. As I understand it, that will only throw off the O2 sensors, but I'm guessing if it is causing the truck to run rich it could have overheated the cats with unburned fuel? Are there any other diagnostics I can perform? Note that I am not showing a CEL, though I would have thought if the cat failed it would throw a P0420 again??
Thanks,
Rod
Thanks,
Rod