I own a 2001Tacoma 4WD with a 2.7L engine. With 245k on the truck, it still runs strong; however, the truck has developed a problem. Yesterday, I tried starting the truck from a cold start and it did not want to idle. The truck would run only if I kept my foot on the gas and the engine revved up; however, when I removed my foot from the accelerator, the engine would die. Could this be an O2 or mass air flow sensor? I just cleaned the mass air flow sensor about six months ago with a cleaner designed for that purpose. I have not seen an error code or a check-engine light on the dashboard, and the truck runs great as long as I keep the engine revved up. This problem happened overnight Any suggestions? Would appreciate the help.