I originally stated:
"My 1987 240 runs great when cold. As soon as the engine warms up it has no power and behaves as though the timing is severely retarded.
It has new plugs,wires,cap,rotor,timing belt,tensioner, and harmonic balancer.

It has been about one month since the above parts were installed and I had no problem until today.

It is not behaving like a bad AMM (at least not like I experienced when one failed a few years ago). Also, it does not smell like it is running rich as a result of a bad O2 sensor.

The fact that the engine is hot or cold doesn't affect its performance. It sometimes runs great and then will have no power for awhile and then run great again.

Also, the catalytic converter is rattling like its internal baffles are loose.

Could the exhaust be blocked??
--
Alan, 1987- 245 and 1996-964 ( last of the RWD'S)