Had the timing belt replaced very expensive they apparantly did not do good job at the timing
On most cars the timing can’t be adjusted anymore, it’s controlled by the ECM. If the timing is off after the belt was replaced they put the belt on wrong. Bring it back and have them redo the job.
Willey is correct.
That expensive timing belt replacement was not done properly, meaning that the belt was placed “one or two teeth off” when installed. The shop that installed the belt owes it to you to do the job correctly. Until they reinstall the belt properly, your fuel mileage and your engine power will suffer.