y just cleaned the engine about a week ago and yesterday i started the car and i started fine but when y got warmed up the revs got going up and down and then it turned on the check engine light. what can this be.

 

Probably the IAC Valve attached to the Throttle body. Intake Air Control valve. It controls the IDLE and when it gets dirty it doesn't adjust correctly. Do a search here/there's lots of info.

 

Yea.. the IAC. Your probably got something stuck in it or it wasnt cleaned thouroughly.. I had the same issue so i just replaced mine

 

What was the code set? First get the code. Then go from there

 

the CEL will generate a code- which any parts store will pull for you for free (except Ca.)
that will point us in a direction

but codes are clues- not diagnosis in themself!

you cleaned the engine--external-pressure wash rinse? spray can Gunk and gentle rinse?
or internal- seafoam or bg or similar fuel product?

external= I would ck all connections to coils and all exposed electric connectors-
wd40 is the tool for this job
wd actually means Water Dispersant, Test Formule #40 = WD-40!!