Originally Posted by stupidtruck
i have a 97 4.0 auto 4x4 and then ever its cold out side like under 40 degrees, after it get up to temp it will start trying to die and stoplights and when in park for a minuet or so the rpms will start bouncing by about 100 rpm. Then sometims while coasting or going down a hill with my foot off the gas the rpms will bounce from 1100 to 1500, and worst sometimes while coming to a stop around 15 mph the rpms will bounce again causing the truck to buck unless i give ita little gas while braking. it throw the both banks of o2 sensors are lean and the evap system is not working right, and ive changed the evap purge silonid and the sensor for it. i have no idea ive done plugs wires pvc valve iac looked at all the visible vacuum lines. but it runs fine in the warmer weather. has any one ever had this problem because im running out of ideas and i think that shops are a joke because they'll fix it but screw up ten other things in the process so you have to bring it back to them. any help would be greatly appreciated as this is my work truck.
Sounds very similar to my nieces VW Cabrio. I had a hell of a time figuring it out.
On that car if the coolant gets even slightly low the coolant tempature sensor winds up not touching the coolant and the car runs horribly.
This was magnified 100x in cold weather.
Just some food for thought.
p.s. The VW Cabrio did not send a SES or CEL for the problem.