Post catalyst fuel trim system too lean ?

I recently purchased an 2008 Chevy Aveo and on the way home the check engine light came on. After having engine code checked it said post catalyst fuel trim system too lean.

I called a mechanic and he said it was probably a MAF sensor, O2 sensor, or catalynic converter going out.

After researching, I keep seeing where an 08 Aveo doesn't have a MAF sensor.

Can anyone tell me if they have had this problem and what their problem ended up being?

Thanks

Posting the actual code would be more helpful. There are many helpful people here who could decipher the code and advise you.

I had that code come up. I'd check the cheaper parts first cause the manifold/catalytic converter is pricey

The code was P2096

Here's a decent explanation of the code and they list a few common things that could cause the code.

P2096 Code Post Catalyst Fuel Trim System Too Lean Bank 1