Sure, about $100 - $120 for a (INNOVA 3100) OBD II code reader an auto
It tells you, for instance, "P0170", which its booklet states is "Fuel
Then it's up to YOU to (a) figure out exactly what that means and (b)
which part(s) need to be changed. So, you see it helps but isn't an
instant answer to life's automotive challenges.
And remember, the air mass sensor is an easily accessed part that we all
can change, some of the others aren't so easily accessed by a DIY owner.
So do you want to take the plunge or take it to the shop?