Check Engine Code PO420
My wifes 2000 Expedition EB with the 4.6L engine check engine light came on last week, took it to autozone and the only code PO420 came up. I disconnected the battery to clear the code, but the same code came back a few days later. I The Autozone Employee suggested a bad oxygen sensor might be to blame. Has anyone in here have any experience with this code?
I also noticed while driving the truck that there is a slight miss under light loads once the torque converter locks up 40-50 Mph. Under full throttle the engine seems to surge a little. I wonder if this could be the reason for the code above?
Any advice would be appeciated.
P.S. This forum is a great source of info for owners like myself. I changed my tranny and torque converter fluid by reading the great advice posted in here.
http://www.obdii.com/cgi-bin/forumdisplay.cgi?action=topics&forum=OBDII+(1996+a nd+up)&number=1&DaysPrune=75&LastLogin=



