[paulzebo]

944 Ecology and Monkey Wrench are correct. the Check valve is only for startup to have instant pressure at the injectors. A bad check valve would have a slightly longer start up time. On the other hand, a sticking fuel injector will make the engine run lean. The stuck injector allows too much fuel into the engine and the computer will try to lean all 4 of the injectors out. Until it's too lean and cannot run on that one rich injector. Techron is one additive mixed with fuels at your station. But only if the station has Top Teir Fuels. Premium has more of the additive precisely to keep those injectors clean. The good news is you can buy it separately or the fuel injector cleaner of your choice. The bad news is it won't be an instant correction and takes time. Removal of the injectors and a good cleaning at a business who specializes in injectors will be the only immediate fix.