Luther Grimace

I have a 2000 4Runner with a 3.4. I have noticed for the past year or so that when you put the pedal to the floor it wouldn't pull. Almost like it is choking. Last night on my way home from work I punched it, it choked and as it came down in rpm then it died. I couldn't get it to crank back up until i pressed the pedal down half an inch or so. I looked up the codes P0171 - System too lean Bank 1, pending P0171 - System too lean Bank 1, P0420 - Catalyst effecieny below threshold. Well i ended up checking a bunch of possible causes like fuel pressure which was strong. Cleaning the mass air flow sensor worked and now it runs like a scalded cat. But I am still having an issue of if I rev it up in park very high the rpm will fall all the way down and die. I can turn the key over and it will be hard to start and if it does it is like 300 rpm and eventually dies again. I can press the pedal down and it normally cranks up and idles normal. This is kind of an oddball problem but it seems like it should not die coming back down from a high rpm. I checked the codes tonight and the P0420 has come back. Anyone ever heard of this? Thanks for any help

rworegon

Vacuum hose leak? Injector issue? Dirty fuel filter?