Bought this truck 2 months ago ran great for 3 days after that engine would sound like it was coming through the hood check engine light comes on engine idles fine goes out engine kicks back up to high idle took it back 10 times to garage they change plugs, wires, put a new after market computer from Fishers in it now if the check engine light is on truck runs fine the truck gets warm check engine light goes out engine sounds like its coming through the hood please help garage won`t give me my money back and I`m stuck

 

Any codes for the check engine light?