I recently had a shop installed a Magnaflow muffler on my truck. I understand that this 92 5.2L has 3” pipe all the way after the cat.

This 18” Magnaflow has 2.5” S.I/S.O and both offset. The shop put 3” before the muffler and 2.5” pipe after. The owner claimed that the different pipe and muffler size than the OEM won’t change/reduce the truck’s performance. Is that true?

I like the Magnaflow’s mild and distinctive tone. I can't feel any performance difference. But when a shop put in something smaller size than before, I just couldn’t help wondering all the possibilities. I wish I caught it when installing. [sm=redx.gif]

Toyou exhaust experts: please chime in your thoughts. Please tell me whether the size variation haunts the performance, or it’s insignificance to even discuss. Thanks.

 

The new size didn't change anything on my '95, I've got a 3" starting right after the Y into a 3" Cat, down into the muffler (3" SI, 2.5" DO) and 2 2.5" out the back, it didn't hurt anything, been on for almost 3 years now

 

Only thing it might do is increase your backpressure a little. Shouldn't be enough to cause ant problems. Unless your fuel mileage or performance has suffered, I wouldn't worry about it.

 

my 93 had a 3 inch, then i decided to dual it out and cut the cat. the stupid *** put 2.25 pipes on and i didnt catch it until it was too late, plus they over charged me and took 5 hours to do it. the guy took his lunch break right in the middle of doing the work. i will never go back to that company, there are several of them around town and they are all the same. years later i took my truck to the same place and told them what i wanted and they said it was impossible. drove across town to another place, told them what i wanted and they said they could do it but it would take some time. now i have dual 2.5 adapter from the manifold, then 3inch into magnaflow highflow cats, then into magnaflow mufflers and out the back with those long slant tips. sounds incredible, i get would everytime i drive now. took about 4 hours and $550, but it was well worth it.

 

In the future I need to re-do the exhaust on my truck. I believe the number of exhaust clamps was counted up as 9.
I'd like to go with dual exhaust, I'll just have to get my truck back and see how I'll run all the pipes.