Ok first off I have a 2001 S60 2.4t. It ran fine til I put it away for the winter, Then when I tried to get it back on the road the battery died. So I replaced the battery and that's when all the trouble started. Now when I start it it sputters and sometimes dies out. but once it sputters enough it sounds normal but when i try to drive it it seems sluggish and doesnt want to climb over 2000rpm's. Any ideas??? Thanks.

 

Your catalytic converter may be clogged, plugs fouled, coils cracked, etc.