My issue is that my car keeps shutting off when I'm on the brakes to long or at the light for to long. It can't idle longer then 2-3 minutes. The air sensor was replaced. I had somebody tell me it was the main computer at fault. So I replaced the computer, and the service light went off and the car worked great, it stopped stalling and I could idle fine. But out of nowhere after two hours of driving the service light came back on and the car started stalling once again. So I thought I would finally ask for help online. Thank you

 

Why Does a Car Stall When You Brake? | eHow

Check for vacuum leaks.

 

And / or loose , defective , or otherwise messed up sensors , wiring or connecters .

But you hit it right on the head , brakes -> more likely vacuum problem .

My 96 Lumina ( when I started tracing down vacuum lines ) proved to have an absent vacuum reservoir ! No answer for that , I bought the car used in the late 1990's .

God bless
Wyr

 

Agree with the vacuum issues. I once knocked off hose to the fuel purge canister! oops!

original poster should look for dry rotted vacuum lines too.