heres the thing... i have 1991 240sx. 5 months ago i changed my spark plugs and cables and then i messed up on the cable numbering, i mixed it up in short then i took it for a spin. while im driving i saw smoke coming out in my engine so i went back home and i checked everything and found out the spark plug cable were mixed up. when i corrected it i took it for another spin and then heres the problem. its not as powerfull as before. i mean, i cant even screech my wheels on first gear then as shifted to 2nd gear i feel some lose power.

hope anyone can explain me what happened and what to do.

Thanks a lot...