I give you more credits for smarts than that post indicates Audiboy ^^^^^
I'd be caring.... If something goes bad, then he wont have an extra 50hp.... he wont have any hp at all.
Might be worth asking the question but O2 sounds right but the car is still pretty young?
It is possible you gotta bad 710, you could upgrade to the 710 n sports.
Does your car blow any black smoke at all?

 

No, I dont see any black smoke.

 

Actually I think the you're still getting 50 hp was in reference to the gas mileage statement not the running rich one lol. I could be wrong though, it's happened before.