Replaced the rear cat converter on my 87 GL 4WD wagon today. It had developed a really annoying rattle in the exhaust, especially when just warming up, that would quiet down when exhaust was hot. Pulled the rear pipe with cat, shook it hard & the biscuit came loose inside.
Cheaply made cats just don't last. The biscuit was so loose it turned sideways inside the body.
Chopped it out right next to the cat body. Replaced it with a Magnaflow 91004 (same length+width+depth as original but 2" in & out). The 91004 has only one heat shield so I liberated one from the old cat, tack welded that to the new cat. Aligned everything in the exhaust, tacked it together then removed the assembly for final welding. Put assembly back in, checked alignment so nothing hits & cinched down the hardware.
Found out later that the Magnaflow 38104 will also work for this application.
No more noises like chicken bones in the garbage disposal.