Facelift Differences ExhaustAight getting into the mysterious stuff, accurate exhaust diagram for 2.5i's are apparently forbidden on the internet?? Most online parts stores don't even list the correct diagram
DifferencesBoth the
Pre-facelift and
Post-facelift share the same mufflers (including other trim levels), im unsure whether the 2.5i midpipe/y-pipe is the same as other trims, but considering they are different between
Pre-Facelift and
Post-Facelift I would think they are not.
The midpipes are relatively the same between facelifts, except the pre-facelift is slightly longer at the front. J-pipes and headers are completely different between the facelifts but are interchangable with some work.
o2 sensors on the
Pre-Facelift are located at the front of the engine on the J-Pipe and at the rear of the engine also on the J-pipe.
o2 sensors on the
Post-facelift are both located at the front of the engine on the header.
InterchangeabilityHangars are the same across facelifts so it is possible to swap everything from the header to the midpipe/Y-pipe without modification (except for the use of o2 sensor extension cables).
To change headers and J-pipes between facelifts you can get away with using either midpipe but you would need to either lengthen or shorten the front of the midpipe to make it work.
Just changing headers would take a lotttt of work, and you could end up coming out of it with an extra catalyctic converter, true econobox spec. CEL might get a bit fucky if your unlucky as well.
These diagrams apply for the standard 2.5i's and not the weird ones like the californian PZEV model.
Pre-FaceliftSeemingly hidden from public eyes this was taken from a subaru technician manual and edited slightly.
Post-FaceliftThis is what will come up when you search for a gen 4 2.5i exhaust diagram, even when you put in
Pre-facelift years. Dont be a dumbass like me and order parts that suite this setup when you have a
Pre-facelift and then only realise when they get delivered they dont fit