I did maybe the stage three exhaust mod, deleted mid-muffler and dynomax resonator. Anyway, I want to put the mid-muffler back on because it killed my MPG, by about 5-6 miles. I wanna do a magnaflow mid-muffler but can't find the part number. Can anyone help??

 

there are other forces at play for your MPG loss.

 

Like what?? Car runs like a top no check engine no noises, nothing.

 

first off. a muffler delete cant decrease mpg. what decreased your mpg was you flooring it to hear the exhaust. and no one keeps the mid mufflers, so youll prolly never find a magnaflow one.

 

My 55 year old mother has been driving it since May, when I took my trans am out of storage. I highly doubt she's flooring it to hear the exhaust. Thanks for the useful info though.

 

It's a hollow piece of metal that weighs 14 lbs. It has no mechanical or moving parts that have any bearing on the function of the engine or its output.

99.98% of everyone who removes the MM have never had any similar issue in the past.

So looking at this logically we can say removing the MM was not the issue.

You said your mother was driving it? My first thought would be to find out if she put the 87 octane gas instead of Premium. It happens.

TLDR; Its not the MM, no matter how much you want it to be.

 

to give us an idea about your poor mileage, post up the info from the MID.
this includes average MPH and average MPG, which can be found in the MID.

 

If anything, deleting the MM would improve gas mileage (by .01% )

 

More than likely she is putting 87 octane in it...I'm going to be using it next week so I'll put premium and reset the MID then report numbers.

 

Yeah no way it's the mid muffler, it's straight through. I replaced mine with a Flowmaster Super 10 (chambered not straight through), still get the same mileage.

 

Agree with the others, no way removing the mid-muffler is going to affect gas mileage. Or performance.

 

There's no way its possible, I have stage 3 mod, and I haven't seen much difference. I may be getting like 2 mpg less just because I floor it often now just to hear that sweet sound. But if you haven't changed your driving habit, then there's just no way its possible.

 

MID shows 23 combined

 

If you need a mid muffler i have a spare.