Negative effects from running without a muffler?
 

The local muffler shop here is know for removing the muffler and just replacing it with a Y and 2.5" tailpipes. from what I have heard, the trucks sound pretty good but I have not been inside the cab of one running straight pipes like this. Cheap enough alternative to a aftermarket cat-back system I'd think. My question: what will this hurt over time? any loss in hp or mpg? On my last truck, not a ford, I removed the gibson muffler I had on it once it rusted out and replaced it with a Y. soon after it began eating $100 02 sensors and after two of those, I put the stock muffler and pipe back on. it also ate one sensor while the gibson was on it yet my other identical truck with the stock exhaust never needed one replaced. thiese fords have what, four o2 sensors on them? (I should go look) but I know they are hidden, pretty hard to get at and likely more than a few bucks to replace. thanks.

the muffler shouldnt hurt your o2 sensors as it is after them. I dont know exactly what you would lose or gain as ive never seen a dyno test. I took the muffler off of mine just for an afternoon and hated the sound. It sounded like i had a giant exhaust leak ehich basically it did. Plus it seemed like it took forever to rev so im guessing i lost a few horsies.

My neighbor did this and IMO it sounds like crap. I would suggest saving your money and getting a cat back system.

you'd wind up with flat tires out here with no mufflers...(slashed)