I went to AutoZone and had my CEL codes scanned. The employee hooked the reader up to their computer and told me the CEL came on because of my PCV valve. The valve that is currently on there is only 4 months old so I assumed it was the grommet (because of age and because the pcv valve just slides out with barely any resistance or effort) and tubes/hoses (they looked incredibly aged and dry rotted plus was pieced together with broken pieces of plastic tube and rubber hoses and connects the PCV directly into the side of the throttle body where the coolant lines branch. After doing some research and poking around, I found that the PCV valve hose assembly is also supposed to go into the back of the throttle body/Intake manifold. After feeling around, I found the nipple it's supposed to connect to, but it has been capped off. So I've been stuck wondering a few questions. Could the new PCV valve be bad so fast?, it still rattles fine. Could the CEL and code be caused by the old grommet and hoses? How tight should the PCV valve fit into the grommet?, because the current one just seems lose to me. Why would the previous owner have capped off the back PCV nipple and is that bad or could there be a good reason for it? Are aftermarket PCV valves worth it or stick to the motorcraft ones? One of the coolant lines that branches from the side of the throttle body where the PCV hose connects leads to where the air intake meets the throttle body and hooks Into the side of a random plug? Can anyone tell me what the plug is? Thanks ahead of time for any help or Info guys.