Take a good look at the flanges. I chased this for a long time. Look for a reddish discoloration where the flanges that mate to the manifolds meet the pipe. You also want to take note if the ticking is more pronounced at cold or when warm. The best way to diagnose this would be to take a 2'-3' length of small diameter hose and "listen" around the flange using the hose like a stethoscope. That is how I found out my flanges were cracked. The cracks are probably really small. I had mine welded up, with strong discouragement from the shop indicating that the welds wont last long. Oh well, I guess I will find out. Also, a word of wisdom, if you do take the "Y"-pipe off, order up new gaskets and a stud and nut kit. This will make life much simplier, trust me.
--Kris
