If i had bad plugs or plug wires could this cause the 171/174 codes at the same time? I did a scope on my car the other day and cyl #6 was getting 20kv at idle, while cyl #1 was getting about 15kv. Timing was good in all cylinders. Vacuum was 17"hg at idle and about 20"hg at 2000rpm. I know my hoses are all good, so I will check my gaskets with carb spray. I am hoping my UIM just needs cleaning - but I don't know if both bank 1 and 2 would be running lean because of that?
