I need some info on my 99 ss camaro with a 5.7 v8. I took it to a mechanic today since I have been having codes popup and it lacks power and doesn't run as good as it should. They did a smoke test on it and found a big vacuum leak at the back of the motor and they told me it was the pcv valve and or hose assembly. But since there is no way to get at it, they told me they had to take the intake manifold off in order to replace the hose assembly and pcv valve?????? I do know you cannot see anything on the back of the motor but was looking for a diagram to see where it is located but I could not find one and my haynes book does not show it. Also was qouted 3.5 hours labor plus $109 for the parts. Please advise if this is correct. Thanks JT