A/C on engines runs erradically?

[reno]

When I run my A/C for awhile (like 20 minutes or more) and come to a stop, the engine idles way down then levels off. Also I noticed it spits and sputters occasionally while driving at highway speeds or stop & go traffic. Temp guage does not show a heating problem. I have a 4.0 5 speed 4x4. No codes or CEL.
When I turn on the A/C and the clutch kicks in, it does idle up like it should.
Anyone have an idea what it is?

-=Reno=-

 

[MAKG]

Have you run all the self tests yet? "No codes" is a serious fault; you should have three "pass" codes (111 on your year), one for each test.

An idling engine produces very little torque. The air conditioner takes much of that up, at idle.

Spitting and sputtering points to an emissions problem of one sort or another. This is not explainable by the conventional air bypass excuse if the throttle is open even a little.

If the self tests are clean, have your air conditioner checked. A blockage or overcharge could explain bogging down after some time (excessive high side pressure) that is absent when first turned on. A loose blockage might take minutes to take hold.... Blockage would result in poor refrigeration.

 

[reno]

Yeah I get the 111 pass code, now, when I first got the truck I had 173,175.