uncontrolled idle

Mt 1999 Trooper 3.5 with under 50,000 miles has developed an idle that fluctuates and some times refuses to return to idle, staying at about 2200 rpm when coming off throttle to coast or stop. The code comes up
as lean mixture oxygen sensors. anyone else have this problem? Automatic transmission. Ron
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What code number(s) exactly are you getting? There is whole slew of them, and there are 4 oxy sensors in that vehicle.
Wild guess: check your intake manifold gasket. Mine just went at 130K miles, but others have experienced it to fail much earlier.
Peter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.