solenoid blues

hey hope all is well with everyone....my question is about my 07 2 wheel drive 5.7 having problems with it stay in 4th gear. I changed SLU pressure control solenoid (torque converter) and I changed a shift solenoid S3 C the codes do not identify which one specifically. When I changed the SLU had no change in the performance still would not shift then I changed the S3 and it drove fine for a few miles then went back to not shifting the only change I see from switching the S3 was during down shifting the trans was a little smoother but hers the thing there are 5 shift solenoids and 4 pressure solenoids what is the best way to pin point the faulty part? I really hope someone can help me out thanks