whats a good muffler to get for my ls that not only sounds good, but also improves my fuel economy????

 

The stock one.

 

magnaflo

 

SS/SC exhaust with a muffler if anything.

 

you will need a tune to actually improve the milage with any exhaust

 

Not true, when I installed the ss/sc catback onto my LS I gained about 2mpg.

 

I gained nothing MPG wise, but it is a bit deeper.

To the OP get a custom bent exhaust with with a magnaflow muffler. Go with 2.5in tubing...

 

most bolt ons that don't require a tune can increase mpg
in therory anyways.
a power increase without increasing fuel delivery requires less throttle
position or opening to achieve the same engine speed.
unfortunately most people like the extra power and hotrod
around, hence decreasing mpg.

 

i am geting the magna flow do i have to get a center in center out to keep the stock hole or do i have do get a different one...whats best type of magna flow for the 2.2 ?

Buummppp

 

Yes you need a center in/out

 

x2

I doubt replacing just a muffler will make you see any noticeable gains in economy.

 

You will need to replace whole exhaust to see gains. Keep your foot off the gas if you just want better mileage.

 

megan

 

Straight Piiiiiiiiiiiiiiiiiipeeesssssssssss Maaaaaaaaaaaaaaannnnnn

 

just to clear it up for the muffler i am ordering does it have to be center in and center out....i read up a few that i have to have center in and center out but then read in another thread that it doesnt have to be helps lol

 

doesnot have to be no

 

The Cherry Bomb Vortex muffler is very free flowing and has a nice sound to it. Mine is a 88101? I think and it is open inside with a plenum in the middle. The best muffler I know of and well worth checking into.

Just for everyones information here my car is a 2.2 HHR and I read this forum becuase we have the same motor and chassis and so many things are the same.
On my car I have put a complete 2.4 exhaust system including downpipe and cat then put the Cherry Bomb Vortex muffler on there. Runs better and gets better mileage to. But I now suffer the same problem as many of you, it runs better so I keep my foot in it more......