josephf31 wrote:
Quote:

istter1 wrote:
Well lost 3 cats at same time.
One theory rear cat clogged first making precats fry.
Next. Vet slow start first time in morning. Excess fule in cats caused them to.melt down.
Next they were old and all failed at same time.
Tomorrow. Compression test
Fule pressure test
Injector test
Make sure the 50000volt coil is working correctly.
Already cleaned out mufflers.
Exaust sounds great now.

Anyother suggestions.

Main cat on my '91 was completely (and I mean completely, nothing but a metal shell) blown out. Still failing emissions I think the precats are likely shot too.

How did you determine all 3 cats bad, did you pull and inspect them all?

As for the slow start, I'd begin with checking the fuel pump that caused a of problems on my L98.