P2135 - what should i try 1st?

[avguy]

A real-time data stream scanner might be a huge help in diagnosing the issue with your Aveo. Seeing key parameters such as fuel trim, TPS %, MAP, etc can often be very important in diagnosing the actual issue. And a multimeter would be another important tool to have, if you get into measuring sensor voltages. If you're not interested in going that route, I believe the part-hangers have had the most success with a throttle body (i.e. a TPS) for that group of codes.