So I don't have an AFR gauge and the only power mods i have are a T1R intake and a custom cat back exhaust, and about a month ago i switched from 87 octane to 91 octane.

But whenever I start the car and let it idle there's a definite smell of gas coming out of my exhaust, I think it may have gotten worse after switching to 91, but it's too hard to tell. So is that normal to be smelling gas fumes come out my exhaust at idle?

I can say though that i usually get 480-510km before my fuel light comes on.

 

you get way more kms then I get so you're not running rich. Mine is bone stock :P

It's normal to smell gas, do you still have a cat converter?

 

yea i still have the cat converter, out of curiosity how many km's do you usually get?

 

I don't think I'm a good example since I mostly drive my car to and from the ctrain station which is about 5-6 kms away so my car barely ever has a chance to warm up.

I got 410kms before the light came on this time. During this time of year it has been around 380-420kms

 

Why not just stick to good ol' 87 octane?

 

I thought it might help the performance since i don't really have any money right now for performance parts, and i did notice a difference with the first tank of 91, but i think my ecu adjusted after that, and now i'm a little scared it may hurt the engine if i switch back to 87.

 

The Fit is designed to run on 87, a lot of people actually reported get better mileage out of it.

There is actually less energy in 91 octane fuel, the primary reason to use a higher grade of fuel is simply because it is better for higher compression engines. The only exception for the Fit would be if you are in extremely hot temps (like Nevada) and want to prevent knocking or if you have upgraded to an FI system of some kind.

Really the Fit is right at home using 87, you shouldn't have any concerns about the ECU adjusting if you want to switch back.

I love the fact the Fit is designed to run on cheap gas, it seems like all new cars require premium these days!

Anyway hope that helps

 

Yea i think it adjusted alright, I had half a tank of 91 left yesterday and filled the rest with 87 and by the end of the night i think it had adjusted just fine.