Had a rebuilt engin installed in my 99 camary. The mechanic tells me the computer is not communicating. The battery has been disconnected for @ 2 to 3 weeks. Dose the computer need to be rebooted or something.

Computer had worked when he started woking on the engine.

He must have done something to it.

Of course you can get a cheap one at a junk yard to check the original.

Good luck,

Sam

mechanic tried a used computer and it did not work eather

mechanic tried a used computer and it did not work eather
Just reread your post. So it was a different engine that your mechanic installed.

I am not a mechanic but would start with simple things:

Spark,

Fuel,

Air (MAP or MAF if you have one).

Good luck,

Sam