Thursday, March 29th, 2012 AT 12:31 AM
It also idles really high at around 800/900 rpms and shifts hard and delayed. When in the cab I can hear a slight knocking sound when it idles from the vibration of the engine and it's really rough. The fuel economy is rapidly decreasing, I go through about 1/3 of a tank a day and I only drive about 20 miles combined to and from work. When breaking I can feel the truck sputtering and at a complete stop it almost always feels like it is going to choke up and stall out. The oil pressure is also slightly erratic, but that's a new problem. It always starts back up, but very rarely I have to give it a little gas for it to turn over. I've ran a fuel line and fuel injector cleaner through it, replaced the TPS and fuel pump, had a complete tune up, checked the air filter and all of the fluids. What is causing this?