blocked CAT

Hi does anybody know the symptoms of having a blocked CAT???Ive been loseing power and feel as if the engine is spluttering for short periods???

What age car?

1990 import

Doesn’t need a cat, but check the front pulley it is more likely to be the crank pulley coming loose see

 

 http://mx5oc.co.uk/forum/forums/t/228.aspx

 

 http://www.miata.net/garage/hsue/crank/loctite_1.htm

 

 Might be something less serious.  Could just be misfire due to the plug leads breaking down - that’s quite a common problem.

not been able to get spark plugs out yet but the leads look allmost brand new!covered the engine and the airflow metre with a sheet last night and it drove like a dream this morning!!!

sounds like leads first then [:D]