Is there torque specification on the bolts for y-pipe?
I tighten those pretty hard with a box wrench. I guess is that when the bolts heat up when the engine is running, they expand and might crack the pipe. am i wrong?

 

the OEM torque specs are in the attached diagram. it looks like 40 ft-lbs will work for both ends of the y-pipe.

 

Thhx for the diagram. I hand tightened the nut with a box wrench (normal length) pretty tight. Is this far too weak to reach 40 ft-lbs?

 

You should be fine. I torque mine down to around 70 ft pounds. No problems ever. Exhaust bolts (minus the headers) aren't that important to worry about torque specs.