about 3 weeks ago i had the timeing belt replaced after it broke and now its ideling rough and has no power.....we replaced spark plugs, cam sensor, and O2 senor thinking it might run better. When we reset the computer it runs fine and the check engine light goes off, but when we shut the car off the check engine light comes back on and it runs bad....when the mechanic ran the computer to see what the problem was it shows nothing...is there anything we can do?

It sounds like maybe the timing belt isn't on right. Could be a couple cogs off.

our mechanic readjusted the timing and still no improvement...This is so frustating...Do you think it could be in the brain?

I'm not saying anything bad about your mechanic, but perhaps you should try another one. If he has exhausted his resources, somebody else may have better luck.

If your check engine light is on there certainly should be a code to retrieve. Since you said the car runs fine after the computer is cleared, I would say that your timing is ok. Sounds to me like an electronic problem somewhere.

If the engine was running at any kind of speed when the belt broke, you may have had valve to piston contact. If so, you may have one or more slightly bent valves that will definitely make the engine run a little rough and not show a code. I would have the compression checked in each cylinder. The compression should not be less than 100 psi in any cylinder and no cylinder should be 15 psi, or more, less than any other cylinder. If either of these conditions exist, you will need a valve job. Caution: Waiting to long to check this will beat the valve seats out and could cost upto and including a new cylinder head.