3.7 exhaust question

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Redd37

Junior Member
Joined
Jan 16, 2022
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Location
North Beach
Ram Year
2007
Engine
3.7
Hi all, I tried to attach a Flowmaster 40 series to my 3.7 because I was told the exhaust we run stock on an 07 1500 is a 2.5” when in reality it’s a 2.25” could I just throw a 2.5-2.25 reducer on both ends and call it a day? Would it still pass MD emissions or will I need to keep an OEM muffler in my parts bin? I currently blew out my outlet on my stock muffler and legally can’t drive my truck but hey, it is what it is. I know it’s not very good for the engine but I kinda like the sound on the low end with it disconnected
 

HemiLonestar

Senior Member
Military
Joined
Jun 1, 2012
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5,991
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Location
MD
Ram Year
2016
Engine
5.7 hemi
MD emissions is all about when you drive up to the inspection station (or the DIY kiosk) and plug into you OBD port. All they look for are codes (and only certain codes). A U code with the TCM in my Magnum caused it to fail; didn't give a **** about the open airbag code lol. As long as the rest of your emissions system is good and you don't have engine or trans codes you should be fine muffler or not (unless the tech says otherwise I guess; I've always used the DIY kiosk so I've never had this problem). You can use the reducers but up here you're probably gonna be replacing the rustmaster within a couple/few years.
 
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Redd37

Junior Member
Joined
Jan 16, 2022
Posts
2
Reaction score
1
Location
North Beach
Ram Year
2007
Engine
3.7
MD emissions is all about when you drive up to the inspection station (or the DIY kiosk) and plug into you OBD port. All they look for are codes (and only certain codes). A U code with the TCM in my Magnum caused it to fail; didn't give a **** about the open airbag code lol. As long as the rest of your emissions system is good and you don't have engine or trans codes you should be fine muffler or not (unless the tech says otherwise I guess; I've always used the DIY kiosk so I've never had this problem). You can use the reducers but up here you're probably gonna be replacing the rustmaster within a couple/few years.
Haha rustmaster, that’s great. I appreciate the help man
 

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