Hello and welcome to JustAnswer!
What exactly was repalced? Was it just the bare block and the pistons, rods, crankshaft, etc out of the old block were put into the new one, or was it a replacement long block/short block?
Was the crank replaced?
How much material was taken off the cylinder head exactly?
What kind of shop did the work?
Do you have a receipt showing the part numbers so I can see exactly what parts were used?
Why was the block replaced?
Do you have the car, and have a voltmeter to do some electrical testing?
I assume you didn't have this code before the work was done?
How does it run, especially at idle?