After changing head gasket on 1999 Chevy cavalier engine is running rough why?

Maybe you need a few adjustments or just let it be engaged. Some headgaskets like the Volvo head gaskets need some time for it to run smoothly.|||Probably you have a leak.|||first thing to do is to check the compression, then make sure the spark plug wires are correctly installed.While checking the compression also look at the spark plugs to make they are properly gapped. Also make sure the connectors to the injectors are firmly attached...If you have a compression problem, you may listen for popping , which maybe caused by push rod that is out of line.....plenty else that shpuld get the basics out of the way|||Could have a vacuum leak , crossed a plug wire, timing is off, lifter not pumping up,didn%26#039;t change the plugs and they are fouled, trouble code in the computer. I would check these. Normally you%26#039;ll find your problem is something overlooked.