I have a 1993 ssei with K&N RX-4750 filter 80 series flowmaster muffler and a 180 drilled thermastat, NGK tr6'*. what size pulley would run good all seasons. Also im not quit sure if a sound system can contribute to power/ :? (KR?) problems.

Your spark plugs are too cold for a stock pulley. Maybe even for a 2.2".

If you own a scantool, buy the 2.2" and be prepared to buy the 2.3" if you get KR. Otherwise buy the 2.3" for safety. I strongly suggest checking your fuel pressure before you buy either. We're seeing alot of series 1 cars lately that are reaching the limit of the fuel pump and regulator lifetimes. Running lean at the top end with a smaller pulley under boost is a bad, bad, bad thing.

thanks a lot Iv'e checked out my plugs and they aren't the NGK'*, i put that assuming they were. thanks a lot for the information i'll look into the 2.3 and 2.2!