2007 Ford Mustang car

Tiny
I3BABY23
  • MEMBER
  • 2007 FORD MUSTANG
  • 4.6L
  • V8
  • RWD
  • MANUAL
  • 89,234 MILES
Hey my name is ivan an I have a 2007 mustang gt. My problem is my engine light keeps coming on for some reason. Got the engine light check, code reads p0171 an p0174. K first I change my fuel fitler and a oil change, then my o2 sensors but just two. The ones before the convertor, then the maf sensor, then I got my fuel injectors clean but light still on. I reset the battery for 20mins an it went off but came bac on. But I do hear like a loss of pressure sound when I turn the car off. An I dont kno how to check for vacuum leak please help
Do you
have the same problem?
Yes
No
Thursday, April 9th, 2015 AT 7:14 PM

6 Replies

Tiny
CARADIODOC
  • EXPERT
A common cause of those codes on Fords is the EGR valve. Replace it. Don't bother trying to clean it.

To check for vacuum leaks, start with a visual inspection of the hoses for cracks and dry-rotting. You can also spray water over the engine while it's still cool to see if it gets sucked in somewhere. If you have access to a smoke machine from an auto parts store that rents or borrows tools, inject the smoke into a vacuum hose or the intake manifold, then watch if it sneaks out somewhere.
Was this
answer
helpful?
Yes
No
Thursday, April 9th, 2015 AT 7:21 PM
Tiny
I3BABY23
  • MEMBER
But wont the egr valve code come up
Was this
answer
helpful?
Yes
No
Friday, April 10th, 2015 AT 12:39 PM
Tiny
CARADIODOC
  • EXPERT
Nope. You get an EGR-related code when the computer detects a problem with the sensor on it. Codes 171 and 174 refer to both sides of the engine running lean, but the computer doesn't know why. We know that a failing EGR valve, (failing mechanically, not electrically), is the most common cause of repeated lean codes.

To say this differently, you'll also get same lean codes if there's a vacuum leak. Again, the computer has no way to detect that mechanical problem. It just knows the exhaust is too lean, but it doesn't know why.
Was this
answer
helpful?
Yes
No
Friday, April 10th, 2015 AT 10:55 PM
Tiny
I3BABY23
  • MEMBER
I did some researching an I saw that my car don't have a egr valve. I tried even looking for it an couldn't find it.
Was this
answer
helpful?
Yes
No
Saturday, April 11th, 2015 AT 6:59 AM
Tiny
CARADIODOC
  • EXPERT
Then you'll have to start with vacuum leaks. To check for vacuum leaks, start with a visual inspection of the hoses for cracks and dry-rotting. You can also spray water over the engine while it's still cool to see if it gets sucked in somewhere. If you have access to a smoke machine from an auto parts store that rents or borrows tools, inject the smoke into a vacuum hose or the intake manifold, then watch if it sneaks out somewhere.

I show an EGR valve for your engine. If there is one, it will be shown on the emissions sticker under the hood.

Also check the fresh air tube between the mass air flow sensor and the throttle body. Any leaks there will let in air that isn't measured, so no fuel will go with it. That will cause a lean condition.
Was this
answer
helpful?
Yes
No
Saturday, April 11th, 2015 AT 11:23 PM
Tiny
I3BABY23
  • MEMBER
Ty for your help but I find out it was the iat sensor never knew it could b that
Was this
answer
helpful?
Yes
No
Tuesday, April 14th, 2015 AT 1:02 PM

Please login or register to post a reply.

Recommended Guides