Well, I decided to check the cat today. The car was running even worse (couldn't get past 3500RPM)
I think the guy lied to me, it doesnt appear to have ever been changed, right?
Instead of dealing with the rusty bolts, I just took the EGR valve off to see if I could get to even higher RPM and if the ticking/fluttering sound stopped. It did both, which leads me more to believe its the cat. [I plugged the intake side with a socket to not creat a potential vacuum leak]
So, with that U bend, it looks hard to hollow out the cat [for more testing]...is it possible with something? Also, are those bolts threaded into the muffler flange? How could I get them out?
Also, do you reccomend an aftermarket cat that splices in or one with the entire pipe and flanges and U bend?
Thanks guys, very right it seems about the fluttering EGR valve!