I admit I've never seen a clogged cat cause a miss, but
it will surely not let the engine breath which is just a
large air pump. If you have a miss, really the only
way to get to the bottom of the prob or at least a
lot further than a lot of things is to put the engine
on an ign scope. A scope can monitor primary
ign waves, and secondary waves. It cna help
determine if an inj is messing up, if there is high
resistance in either the pri or secondary ign, can
compare companion cylinders for for ign strength
or lack of and can really help get to the nittiy
gritty of what is going on..
Problem is, finding a GOOD shop with a tech that
can read scope patterns as in Raster, Parade and
Superimposed. But if you CAN locate a shop that
do a decent scope setup and readout, it can save
a lot of headaches. The other deal is our system
is a DIS system IE a waste spark system so one
can really only see the ign in Super imposed.
Here is an article that might help you. I realize it's
not specific to your problem at hand, but it might
shed some light upon your dilemma.
http://findarticles.com/p/articles/m...07/ai_n8876015
I still have to get mine started as well. I bought a
factory service manual from eBay for 99 cents
and I'm just waiting for it to arrive to start my
fixin'..
Anyway I hope this helps a bit.