Rough Idle/P2610

Hello, I'm a new user because I need help, I have a 2004 Aveo with a 1.6L. Recently the head gasket started to leak so me(thinking I'm a better mechanic then I am) decided to replace this myself. Long story short, got the new gasket in place and everything back together including a new timing belt. Started her up and she has very rough idle :mad:, it stays running but barely when rev'd past 1500 rpm or driving it runs fine, the check engine light didn't come on but it pulled a code of P2610(ECM/PCM Internal Engine Off Timer Performance). From what I've read this doesn't really cause rough Idle? Is this true? Or am I going to have to computer tuned, or did I just mess up the timing(all the marks seemed lined up good)? I know it could be a number of things as simple as a vacuum leak(sprayed starting fluid and it didn't rev up). Just thought I would throw it out there and see what others thought. Thank you for you time! Should also mention it need about 1/4 throttle to start.

P2610 means you had the key in the run position for to long with out the engine running.

Fair Enough, that cant cause the rough idle can it? If the timing is off would it still be a rough ride even at higher speeds? Thanks!

No it wont but bad timeing could, fuel starvation could, air starvation could, make sure your plug wires are in the correct firing order, if two are in switched it could cause a rrough idle or cause a piston to move at yhe wrong time causeing a backfire or worse could destroy an engine.