1996 Chevy Suburban P0174 Code: Rough Idle and Starting Issues in Cold Weather
Hi everyone, I'm a new member and I'm currently troubleshooting my 1996 Chevrolet Suburban C2500 7.4L (454 engine). The vehicle is throwing a P0174 diagnostic trouble code, indicating a lean condition in cylinder bank 2. I've already cleaned the Mass Airflow (MAF) sensor and cleared the code, which resulted in slightly smoother operation for a short period. However, the P0174 code returns shortly after, and the truck begins to run roughly—especially during acceleration. It hesitates and stumbles intermittently, though not consistently. Another notable issue is that the truck fails to start when outdoor temperatures drop below 35°F. Once the engine warms up in warmer conditions, it starts normally. This suggests a possible cold-start or fuel delivery problem. I'm looking for advice on what components to inspect next—such as vacuum leaks, intake manifold gaskets, MAF sensor performance, and fuel pressure levels. Any insights would be greatly appreciated.
Consider checking all vacuum hoses for leaks, especially around the intake manifold. A leak in bank 2 could cause a lean mixture, triggering P0174. Also, inspect or replace the MAF sensor as it may be faulty or dirty. Don't forget to verify fuel pressure—it should be within the manufacturer's specified range for proper engine operation.