94 EX 2.2L Vtec KA MT - My A/C is cold as can be when im on the highway, ut as soon as i get into stop and go traffic, at idle the air goes warm and the engine will stumble, bogging down as if its going to die then will jump back up to about 700 RPM. it will do this every 10 seconds or so, im sure its high pressure in the system but what could cause this?

 

It could be the clutch plate gap is too large on the compressor. You will have to watch the clutch plate while the car is idling to see if it keeps spinning with the a/c compressor pulley.

If the plate starts and stops spinning, you will have to use a volt meter to see if the compressor is getting a constant 12V.

Do not add any R134a unless you have the pressures tested in the system.