have you got the codes pulled yet? if not then go to your local autoparts store and they can pull them for you for free. then come back here and give us the codes and we can help you out.

 

Will do...

 

check to see if your gas cap is on... haha happened once in the 05 v6, quite embarrassing. it gotta be completely closed

 

Its not the gas cap. Listening to the engine it sounds like either there is air getting sucked in or let out somewhere. Kinda like the sound of a deflating balloon. I could just be paranoid because of the check engine light, but is that a normal sound?? I dont recall hearing it before.

 

Check the pipe that connects from the upper intake plenum to the PCV valve on the passenger side valve cover.

 

Just get the codes, man

You can get a cheap harbor freight scanner for $50 or less. It'll come with a book of the universal codes (first 1000), and a CD of all the manufacturer specific codes.

A LOT easier than trying to diagnose it over the internet, hahaha.

 

+1 on pulling the codes, take it to autozone )(FREE)( hsnap

 

usually a vacuum leak, a minor one if theres no noticeable changes in performance

 

but get the codes read for sure

 

Bought a scanner from autozone. $25 bucks, came with a book. Scanned computer on the mustang, read only one code of P1405 which in the book said that the hose for the DPFE sensor was disconnected, hose wasnt disconnected so I replace the sensor it self, 100$, check engine light is now off. Reps to all