Purchased last week with 110K miles. Great car....I think. Took to a reputable import mechanic before purchase. Suggested timing belt change (which I had performed) and replacement of valve cover gaskets. Drove @ 600 miles day I picked it up with no problems, family vacation.......great ride...no problems.

upon return, took out battery to clean cable connections and carriage unit (holder) because I noticed some corrosion earlier. Also took out air filter and cabin filter to inspect (and to verify if dealer replaced as part of bill of sale agreement). Both new. Upon replacing battery and filters, started it up next AM and noticed check engine light with P0431 - Warm Up Catalyst Below Threshold Bank #2. Is this a new problem or something I did when tinkering with my new car. Mechanic did say the C Convertor may need to be replaced around 130 or 140K miles....but checked out ok at the time.

Any help / suggestions appreciated....