Getting my exhaust fixed/Upgrade get better MPG?

So recently a few months ago I had a check engine light on and a ABS light and the VSC lights on. Basically had all the warning lights on, so I took it to a local mechanic and got my car scanned for free. They cleared the codes but told me the codes were due to an "exhaust leak" and it may lower my mpg.

The past 2 months I realized my MPG has been getting worse. I used to get 310 mpg on a full tank, but now I get damn near empty with the light on 250-260mpg on a full tank.

Wallets kind of empty right now so I've been wondering if I should fix it and hopes it brings my gas mileage up or just upgrade my exhaust to a new flow master or something..

 

310 on a full tank?? Ouch!!
Depending where the leak it, it could help you get better gas mileage, if it is after the cat/rear o2 sensor it won't help with anything; however, it if is setting a light then it probably is the exhaust manifold to cat somewhere meaning it could help your gas mileage.--the extra oxygen in the system due to the leak before the o2 sensors will make it appear lean and cause it to add fuel.

 

310 is bad? I thought that was good for a v6 4x4 lol. how much would it be to fix/install a new one?

 

I guess that isn't too bad, I have an I4 and do about 420 lol

Depends on what needs replaced honestly--exhaust manifold would be expensive the piping from there to the cat wouldn't be too bad.
Heck it could be the doughnut in the manifold to exhaust tube that burned out

 

Not too bad. I got around 330 to 340 in my stock V6 prerunner.

 

Just trying to get a quick opinion before, or if I ever do, get it fixed

 

It's summer, Ft W Beach, running a/c alot, mostly city driving? If your average fillup is 18 gallons, you're getting about 14mpg. If 16 gallons, you're getting almost 16mpg. Not out of the ball park for city driving.

 

bring it to a small ma&pa shop, see if they can track the leak down and put a new piece of piping in there.
ex-girlfriends Volvo had the exhaust break on us during a trip to Maine where the mid-pipe met the Y.
35$ later the joint was cut out and a new piece of pipe was welded in. Mechanic assured us the whole rest of the pipe will have to rust out before that weld and pipe give out. saved her $2000 for a whole new exhaust at a big name mechanic.