Vacuum leak and p0171/p0174 codes
I have read up somewhat on the common p1071/p0174 codes and what are common problems that make them show up. I know the pcv valve is one of the leading causes for it if its cracked.
I went to look at my parents expedition yesterday which has the 4.6. Started it up and started looking around for vaccum leaks to start. Immediatly I heard a wooshing noise coming from the back left side of the motor. I got some carb cleaner out and sprayed around some but couldn't find where the leak is.
Could this possibly be the intake manifold gasket?
Where are these PCV valves located? I think I saw one on one of the valve covers but it was in good condition.
The thing that got me about this leak is it seems like its fairly low on the motor, atleast low enough that stuff was in my way and I couldn't pin point it.
Any advice is appreciated, I come from the Jeep world so this is a lot different.