The Ford Explorer name was introduced by Ford Motor Company in the late 1960s as an upgraded version of the F-series trucks. The Explorer SUV was introduced in 1991. The 1999 Ford Explorer was equipped with the option of two different 4-liter V6 engines, or a 5-liter V-8. All three engines have an EGR or exhaust gas recirculation system. This system is responsible for placing unburnt fuels back through the combustion cycle of the engine, reducing pollution. The EGR valve is connected to the catalytic converter via a tube, and the top of the engine.
Open the hood of the Explorer. Visually inspect and locate the EGR valve on the driver's side of the engine, just above the exhaust header. Spray the EGR mounting bolts and the base of the EGR valve with PB Blaster or a similar penetrating spray. Allow the spray to soak into the part for no less than five minutes.
Remove the vacuum tube from the top of the EGR valve by hand. Remove the EGR mounting bolts from the EGR valve, using a 3/8-inch drive ratchet and socket. Turn the bolts counter-clockwise until they are removed from the engine mount and the EGR valve. Place one open-end wrench on the hexagonal base of the EGR valve. Place a second wrench just beneath the valve on the EGR tube. Hold the EGR tube as still as possible, while turning only the EGR valve. Turn the valve counter-clockwise to remove the EGR valve from the EGR tube.
Spray Seafoam or a similar parts cleaner into the EGR valve directly. The active ingredients in the parts cleaner will remove the carbon buildup in the EGR valve. Allow the cleaner to soak into the EGR valve for no less than two minutes. Use an old rag or large cotton swab to wipe the inside of the EGR valve. Insert the rag end or the cotton swab into the bottom hole of the EGR, and wipe the inside of the valve.
Apply a light coating of high heat gear lube or white lithium grease to the threads on the EGR tube. Spin the EGR valve back onto the tube by hand. Install an open-end wrench onto the EGR base, and another onto the top of the EGR tube. Turn the EGR valve only until it snugs up to the tube. Turn the EGR valve so that it realigns with the engine mounting surface for the valve, either counter-clockwise or clockwise. Turn only the EGR valve, while holding the tube stationary with the second wrench.
Install the EGR valve mounting bolts through the valve and into the engine mount surface. Tighten the valve mounting bolts using a 3/8-inch drive ratchet and socket. Turn the bolts until they are snug, then turn the ratchet 1/4-turn farther. This "snug-and-a-quarter" turning method is used to tighten a bolt, without applying torque that can possibly break brittle parts. No torque is needed on the EGR bolts; applying torque can break the mounting tabs off of the valve.
