[01Sentra188]

Hey, I have a 2001 sentra that has been having some issues lately. It is incredibly slow. Foot all the way to the floor, and it struggles to get to 20 mph. Anything above 30 mph is a pipe dream. It threw code p0420 a while back, but I cleared it and it never returned. It also threw a random misfire code slightly more recently, but I cleared that and it never returned either. Now it runs with absolutely no check engine. Cold compression is as follows: 121, 0, 0, 125. Warm is 150, 120, 120, 150. Where do I go from here? I thought it could be the head gasket, but I don't think a head gasket could cause 0 cold compression and 120 warm compression in a cylinder. Where do I go from here? Thanks!

 

[rogoman]

You can always run a leak-down test on all cylinders as backup verification to your compression tests. The leak-down will pinpoint exactly where you're losing compression. During a leak-down test, if you hear hissing coming out of the crankcase, there's your proof for wornout rings.