I want to see if mine works perfectly or not. How do I test it out? I barely get any codes, only rear heated o2 sensor which goes away when i reset, and a knock sensor code which I just put in a few months ago. Thanks

 

I would also like to know the answer to this..

 

A dealer can test it for around 40 bucks. (hand-held scanner)

 

Thanks, any other suggestions other than dealer? Maybe somethign I can find out on my own?