Need help with a code
2004 Ford F-150 5.4 V8- 114K miles, tune up at 97K.
I noticed my truck was running kind of rough and had a hesitation when I'd give it gas from a stop. I went and had the code read and it was P0420, Catalyst System Efficiency Below Threshold (Bank 1). I've been trying to read up and see what could cause these problems and there's a laundry list but none of the problems match up with my symptoms.
When I take off from a stop, my truck feels like it's bogging down, like I'm pulling 50K lbs behind me. However, if I "gas it" then it will clear up. It seems to only do it around 1500-2000 rpms. I'm leaning more towards the passenger side cat being toast, but any and all help would be appreciated.