AYEmike

how many miles do you have on your GS, like i said, get a reading on your car's compression. check the ignition coils.

damiendaz

I have 115,000 miles

raytseng

one more thought is pcv valve which might affect the idle if you haven't switched it, although i think a stuck one would typically cause high idle, not low idle. It's inexpensive to change out, worth a try before you get into expensive tests

AYEmike

hows your idle when you first start the car on? does the rpm jump up or down?

EN_VY

Maybe your catalytic converters are on the fritz

damiendaz

I changed the PCV valve and I'm still having the same problem.
When I first start the car the idle is fine. It just goes low when i'm coming to a stop.

AshburnM3

Check for vaccum leaks when car idles low during braking.

AYEmike

for sure check for vacuum leaks as well, spray that engine bay with carb cleaner!

damiendaz

I found out what the problem was. The CEL came on again and it was telling me that my O2 sensors were bad. But I had just changed them out like a week ago. So I took the O2 sensors off and took them back to the store and told them that they were defective so that they could replace them. When putting the new ones in I discovered small cracks in the air intake connector. I took it off and at the bottom of it there was a big hole. I order a new on from the dealership, put it on and my car is running as good as new.