I have a 3.0, l 4x4, extended cab. I had been getting error codes P0170 and P0174. So I finally replaced the O2 sensors, which I thought were the problem. Did the remove battery overnight and drive all day next day. Next thing I knew the same error codes show as well as some new ones P1400 and P0000. I am stumped.
I would like to buy parts while they are readily accessible ( I'm in Ottawa). I was looking at getting running boards while here.

I hope somebody can point me in the right direction.

 

Wow, u got me on this one!! Those codes don't show up any where in my obd2 scan tools DTC's definitions! I'd really like to know the answer myself!

 

i dunno if it's also on the 3.0L, but there is a elbow on the 4.0L's intake that tends to crack. look at your vacuum hoses. there might be a crack or hole you cant see unless you look at it.