Trouble code P1151

[seanagins]

Last night my CEL came on, I pulled the code and it is P1151? Where should I start with this trouble code p1151? I still yet have to perform the compression check and cylinder leak down test., but figured dealing with the CEL is priority. Please help. Any advice or leads about the trouble code p1151 is appreciated. Thanks in advance.

 

[seanagins]

my ranger is a 1997 with about 139,000 miles on it.

 

[seanagins]

I was told that cylinder 4 has low compression via a relative compression check or balance compression check with a scan tool. Now, I have not performed a compression check or a cylinder leak down to confirm furthermore what is occurring on bank 2...