AC in 98 Honda Civic LX

I have a 98 Honda Civic LX and I am having a hard time figuring out what is wrong with my AC. I startup every morning and come to work (15 minute) and the AC is working fine. But when I try to go in traffic for longer than 15 mins the AC stops working. It is very intermittent and hard to troubleshoot. I took it to the garage to make sure there are no leaks in the system and refilled with new freon but no luck with that.

On another note I am not sure whether this is related or not, the check engine light came on once, complaining about the idle control sensor and did not replace the sensor yet. The mechanic cleared the error to make sure it is not related to anything else because on the same day he changed the sparked plugs and tuned the car. It has been almost a month now and the Check engine light hasn’t come on.

Any help regarding the issue will be greatly appreciated

If the CEL has not come back on, don’t worry about it. If it comes back on, check the codes again and fix whatever causing the problem.

You say the AC doesn’t work after 15 minutes, but you don’t say what part doesn’t work. Is the compressor still cycling on and off? Are the radiator/condenser fans working?

If the system is full of refrigerant the problem may be with the temperature blend door, which controls the airflow through the HVAC system. If the blend door moves when it shouldn’t, it can allow air to pass through the heater instead of the AC, and it feels like the AC is not working.

A vacuum leak might cause this problem, but without more information as to what is working and what is not it’s really hard to say for sure.

Can you provide any more information?