Just picked up an 03 suburban 1500 and need a little help before I start throwing parts at it. It is throwing the following codes: P0101, P0135, and P0161. The truck has 232k miles on it but runs almost flawlessly besides these issues.

I know what the generic code meanings are but not sure if it is in my best interest to just replace the O2 sensors and MAF or if these codes could be something aside from the obvious parts. Any help would be greatly appreciated.

Thanks