Chevrolet Repair: 7.4L code PO175, cat converter, c3500

Question
I have a 96 C3500 with a 7.4, just built the motor and runs good and cranks good when cool.After warmup its sluggish to start and SES light comes on with a code PO175
which is rich on right bank.Hows the best way to find out which injector could be the problem without pulling upper intake.

Answer
Hi Terry....pull the plugs on the right bank and see which plug is wet or is fouled.... is it really the inj...check o2 sensor on that bank for low voltage which would cauce a rich problem on that bank...maybe restricted cat converter....if you still think it could be leaking down inj try a good inj cleaner... hope this helps