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I have a 2004 f150 fx4 with the 5.4. It started hesitating from about 2-3k rpms last week. Today, I took it out and it ran really bad. The whole truck shakes pretty badly up to about 2k rpms and has no power. I have to stay on the gas to keep it running at idle. I replaced the fuel filter, cleaned the MAF, and I just replaced the plugs and coils. My edge read a PO171 and PO174 code (lean bank 1 & 2). It also makes a weird wining sound around 2k rpms. I think the drivers side cat is clogged. Could that be causing this? My fuel pressure is also a little low. The edge says it should be 56 and its only 39-40. I have a video uploading now that I will post when it's done.
Can someone tell me which is the pcv hose? I've spent 5 min looking for a hose coming out of the passenger side valve cover going to the back of the intake manifold and I don't know which one it is. I think I have a vacuum leak somewhere and I think that's the first place to check
Can someone tell me which is the pcv hose? I've spent 5 min looking for a hose coming out of the passenger side valve cover going to the back of the intake manifold and I don't know which one it is. I think I have a vacuum leak somewhere and I think that's the first place to check
@Bryan T Barker is correct (or almost correct?). Technically we should call the crankcase ventilation system on our trucks a NCV (Negative Crankcase Ventilation). system. There is, by design, never supposed to be Positive pressure in the crankcase - and thus NO PCV VALVE. Even though the hose that runs from the Bank 2 (driver's side) valve over to the intake manifold connection is the closest thing to it.
The hose identified in the photo supplies "FILTERED" air, post intake plenum air filter, into the passenger side valve cover. The entire crankcase system (front cover, valve covers, Oil Filler cap, oil pan - etc) is intended to be AIR TIGHT sealed - without vacuum leaks. Already "METERED" Fresh air, post MAF, (mixed with any blow by), is allowed to constantly flow through the crankcase, out of Bank 2 (driver's side) valve cover and into the intake manifold through a tube with 'heater coil' that activates below 35º. This heater keeps the pressure drop from freezing the moisture in the air from plugging it up with ice and defeating the system in cold weather. It truly is NOT a 'positive crankcase ventilation' system. There is NO PCV valve. Just a non-replacable screen inside the driver's side vavle cover.
This is the hose that is supposed to go in that location. I bought it because I forgot that my truck isn't currently using it because of my CAI using a regular hose instead
(Didn't notice one of my kittens got into frame there)
Last edited by ShirBlackspots; Jun 22, 2019 at 12:42 AM.