Grand Prix GXP stock exhaust 2.5" or 3"?

[Bloodpython171]

My car is currently in the shop so I can't double check myself but does anyone know whether the stock exhaust size is 2.5" or 3"?Thanks in advance.

[Scottydoggs]

2.25

[rottonj]

The main pipe should be 2.5, goes down to 2.25 before the mufflers I think.

[BillBoost37]

2.25 on a gp.. bonneville Riv or PA is 2.50

[rottonj]

GXP is 2.5

[BillBoost37]

xp yes...tp no

[Bloodpython171]

Main pipe

[blueguy]

Three things:

1) I moved this to the correct section.

2) My work computer doesn't like loading huge signatures so please downsize it and try again.

3) Go measure the exhaust. Pretty sure I saw no difference in mine compared to the 3800 cars, but the downpipe is the restriction...you're not gaining that much on a stock car with a larger diameter catback.