Just bought a scanner and wouldn't you know a cel came on last night. I found code p0174 left bank lean. I cleaned the MAF and checked the PVC tube for cracks. Checked intake bolts for looseness and other vacuum lines. Just changed fuel filter about a month ago. Air filter is clean. Car only has 34000 miles. I had a 1996 with the same 3.0 vulcan but I noticed some slight changes in the manifold area in the 07. Any other ideas ? I cleared the code but it came back. Cleared it again after all the above checks and haven't driven it much since. One more thing ..could a dirty injector cause this code ? if so would some Lucas fuel system cleaner help ?