Had back pressure & fuel pressure checked, all ok. But Durango has ran like a top the last couple days, not so much as a hiccup. It's been like mid 60's lately and runs great. Can someone please explain why if it's cold outside this dodge runs terrible. I'm stumped!

 

I'd say take the O2 sensors off and burn the ends to remove any crap built up on them because it may be one of your sensors (most likely upstream) is dying and taking longer to send information, but not long enough to throw a code.

 

Whens the last time you've done a tune up and cleaned the throttle body?

 

What year is the durango and engine size? Also is the MIL lite on and what codes are you getting?

 

I would do as hydra suggested. It is very hard to diagnose a problem if we don't know whitch engine you have as master tech's questioned.

 

If you don't have a scanner, take it to auto zone or advance and they will scan the codes for free. If you're sure it's misfiring and it does it for a while, (trust me you'll notice it) it will cause the MIL light to flash while driving and store a "pending" code, if it misfires on the same cylinder again it will then light up the MIL light and change it to an active code. So scanning it even when the light is off might still bring up some pending codes.

 

It's a 2001 4.7 4wd. A's bad as it drives in the cold weather, it has NEVER thrown a light or code.

 

In that case then since everything checks out, I'd go ahead and do what widow suggested and clean up the O2 sensors as those or another sensor is confusing the computer.