congrats on the purchase, and good to see that you bought a original milage car, which is rare in PK for sure. glad that you are not one of those fools who fell for the old scam going on here (12k driven 1999 model vitz,.. LOL!)
as for the oil companies, they claim unleaded but it's still got lead in it,.. it's more like low lead, but even a small amount of lead in the exhaust gasses is enough to kill the cat.
you could remove the exhaust and measure airflow in it (resistance) otherwise i can't think of any other way to check if the cat is choked. i tested mine against skullbox's car. the gap was 2 cars at 100 so it seems that in a few months i'll have to get the work done.
thanks buddy, i'm also glad i kept it, now i have to decide if i want to get a lancer GLX or a slightly used civic for the house. i'm always here when needed.
could be dirty plugs, old transmission fluid, dying airflow sensor, blocked air filter, choked catalytic converter, dirty intake manifold, dirty oil etc...
yeah, i blame the fast and the furious fanatics for the rise in demand for useles mods. only reason i put iridiums in my surf is that they have a higher temp rating and i'll need them when i fit the supercharger.