I have a 07 chevey Silverado 5.3 engine. Yesterday it ran fine.today I started it up and the check engine light is on. I see my oil pressure reads 0. Any ideas what is wrong with it.

Check engine light on would indicate an emissions issue. This requires a scan tool to pull the codes. Your local auto parts store will do this for free( and then try to sell you some parts). You can look up the codes at and get the fix at FreeAutoMechanic.com , most likely reason would be a small evap leak. nothing that would keep you from driving the truck. As for zero oil pressure. Check your oil level first, if that's OK, the oil pressure sending unit should be checked. It would most likely start making bad noises if it actually had no oil pressure.

Jaxer is right check your oil level first. If its ok the its probably a bad oil sending unit or what I've found to be the case at least a dozen times, the screen just behind the sending unit inside the engine. The screens tend to get plugged up and don't allow the sending unit to read correctly. Simply remove the sending unit then remove the screen. You might need a small pick to pop it out. Clean it with carb cleaner then reinstall both.