Idle Issues
 

I just purchased a 1991 Montero last night, I have wanted one forever. I had to take it in today to get it checked and emissions done on it cause Texas is terrible like that and after the shop had my car for about an hour it started idling rough searching but it runs fine and doesn't search in gear. Now the check engine light came on I took it back to the shop but he said he wasn't responsible for what ever was wrong. Does anyone have any ideas how to fix it. I took off the air intake and then put it back on and it seemed to stop for awhile and it started back up again. At a complete loss. any ideas