Hi guys,

I just need to clarify if the stock g37 coupe exhaust bolts at cat to Y pipe , Y-pipe to midpipe and midpipe to Muffler were all welded to the flange or not?
I bought a slightly used OEM G37x coupe pipes and I wanted to change all thr bolts to a newer ones. Thanks!

 

They aren't welded and are easy to take off with some elbow grease. I can't say the same for the demon bolts connecting the headers to the catalytic converters though.

 

I have never seen anyone remove the threaded studs from any of those parts. They might be welded in but I am uncertain since I have never tried to remove them, I doubt they're not welded in tho. Hopefully someone can chime in and clarify to be certain.

I think an aftermarket exhaust would be a good alternative as it will include all new hardware with it and are open flange designed.

 

the mid pipe to muffler has welded studs built in (cannot be taken off) I just broke one and had to drill through...PIA.. the y pipe to mid pipe also has studs welded, also cannot be taken off...cat to y pipe bolts only, these are the only one that can be changed, but big PIA, not worth the effort unless you decide to change to HFC or new y pipe....I know first hand since I did all the above myself... cecrops said it well, aftermarket exhaust are all open flange...

 

Thanks guys for clarifying this. I am just experimenting if the G37 coupe OEM exhaust fit to my EX35 crossover. Right now, the G37 coupe muffler bolted right in to my stock midpipe with no modification. I just bought a slightly used midpipe and ypipe from the G coupe.
The G coupe bolts has few rust and I was thinking about removing them and installing a new ones, but since this will be tough to remove, I just decided to PB blast and clean the bolts that are welded to the G pipe.

My only concern now is the Midpipe to Catalytic bolts. It seems like the Cat bolt has so much rust and the tread might not even hold up for the new G Y pipe install. The bolt is connected to the cat side.

The reason I prefer the OEM G exhaust is the sound is perfect for me. Not too loud.
My EX35 crossover Exhaust pipe diameter is smaller than the G coupe. I am also on a budget and just bought a full G coupe exhaust with 9k miles( muffler, midpipe and y-pipe)for less than 3 Benjamins...