id seriously do that, im 97% sure your cat is good, if you have a stock smec, inj, and 2 bar, the cost will be nothing but your time, especially if you have a 1 piece intake on there! that, and setting the ignition timing correctly that will eliminate a bunch of things and get you too square one, buying a new cat or cheating other things ONLY if this doesn't work, and don't forget the 91 octane...I don't burn cals so no stock option unless I throw a stock SMEC at it, and injectors, and 2bar, and...