Clicking/chirp sounds like exhaust leak...please help.
I just got my truck back from the shop. 2001 f-250 7.3 lariat cc. I had them resurface the manifolds and replace the up pipes as well as delete the ebpv with a blank pedistal and exhaust outlet. The exhaust leak I was having fixed was fixed when I picked it up. The truck sounded much better and had more power than when I dropped it off. However, about twenty minutes down the highway I stepped into it a little...not even a lot and all of a sudden this fluttering chirp developed. It almost sounds like an exhaust leak on crack, but I've thoroughly inspected it today after work and the mechanic that did the work came to my house last night to see if he could figure it out...given it was dark and very cold. He didn't know. He's coming back tomorrow in the daylight. But, I'd like to see if anyone else has had this problem and could point me in the right direction as I may fix it myself. Thanks in advance.