DTC P0171 P0174 - keywords 6.0 idle lean LS2 rough SES
| Subject: | DTC P0171 P0174 |
| Models: | 2005 Chevrolet Corvette |
| with 6.0L Engine (VIN U - RPO LS2) |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.
Condition/Concern:
A customer may have a concern with a rough idle or the SES/MIL light on.
During diagnostics, DTCs P0171 and P0174 may be found.
Recommendation/Instructions:
Complete current SI diagnostics for any symptoms or diagnostic trouble codes set.
If a customer concern of a rough idle or trouble codes P0171 or P0174 are found, inspect for a vacuum leak at the rear of the intake manifold. There is a vacuum port next to the brake booster vacuum supply port. This vacuum port is not utilized on a 2005 LS2 Corvette. This port is sealed with a removable plug that is molded into the intake manifold. If this vacuum plug is missing, or the port is broken, the intake manifold will need to be replaced.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
