You need to run a cylinder differential leak down test to find out what the issue is. If the cylinder has low compression it could be bad rings, piston, block, a valve, head, head gasket. A leak down test will pinpoint it. If the compression and leak down test passed then you need to look into an injector issue.

 

Compression is good on all cylinders but cylinder 1 has 0. There's a sound coming from I think the intake that sounds like an exhaust leak but coming from the intake side. Scan keeps showing a code for the MAP sensor but I replaces it and reset the codes but it's back. What could be the problem here?