2001 Yukon

Intermitant problems are the worst. Idle problems are usually fuel mixture control problems. It stalls on turns because you are puting a load on it. There are many things that can cause this condition. Vacuum leak is one of the biggest. MAF, injectors, Idle air control valve, TPS, and so on are also possible. If you got a lean code. You want to look at the short term fuel trim. That will tell you a vacuum leak is a good possibility. If you have someting else going on you need to get a scanner on it with recording capabilities. Hook up the scanner put it on record. Drive it till it acts up and hit record. It is called taking a snap shot. Then you can look at the recording and see what is going on, what the different sensors are saying. A lab scope can tell a lot too. If you don't have these tools call around and find some one that can do this.

I was able to find a mechanic who hooked it up to a scanner for me. The IAC should have been around 300 but it was less than 100. He recalibrated it for me and it seems to be doing fine. The car has 85K miles on it and he said he may need to be changed in the near future.

Thanks