The "Service Engine Soon" light came on in my dash and I took my truck in to see a mechanic. He pulled codes PO171 and PO174 saying that the fuel is too lean on bank 1 and 2. My truck is still driveable. The mechanic stated that I may have a "Head Gasket problem" or a " exhaust manifold problem." My manual says to check the gas cap and put a higher grade of fuel in. I did that and no change. What could be the problem?

Does anyone know anything about conversion vans? I have a 1998 Chevy Astro Gladiator hi-top that has a "battery reset" button on the dash. Van was sitting for at least 30-45 days when I realized I needed to drive it to keep the battery from going dead. It was a little weak when I started it up - but I figured it would charge itself up on the 75 mile trip I was about to make. Sounded funny again when I re-started it several hours later, and again the following day. By nightfall of the second day of use, it wouldn't start - wouldn't jump. Don't know the age of the battery - only had van about 10 months. If battery is truly gone - would that explain why it wouldn't jump? We even tried bypassing battery and hooked my battery cables to other vehicle's battery - still no start. Did have lights though, and a faint click when attempted to start. Tried pushing the battery reset button, but nothing there either. It usually has an illuminated red light - which was not glowing anymore. Maybe it doesn't work when battery is dead?? Have had other electrical issues with this van and no one seems to want to work on them. If battery is not the problem - what do I check next?? Having battery tested today when I get off work.