Sounds about right. They should run about 125 US from GM. Yes, it COULD set a light, but it would set a code, too.

A tranny flush should run you about 80 bucks, and maybe buy you 3-6 months, depending on the trans and your driving style.

No gaurantees. It'* a risk. It could make it worse, depending on the condition of your TC. Without being able to get my own scantool on your car, I can't tell you any more than that.

do u have to remove the engine or trans to replace this?