jschwartze

I had the stock muffler cut out several years ago and replaced with a magnaflow muffler. Now I have noticed that I have a exhaust leak that is before the muffler. A lot of air is coming out of it. Would that have anything with me losing 1 to 1.5 mpg?

thunder550

iTrader: (70)

If the leak is close enough to your O2 sensors, they will detect a lean condition and dump a lot of extra fuel to compensate. If the leak is at your muffler though, I don't think it's close enough to the O2s to have any effect.