• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

Can a Vacuum Leak cause the engine to misfire?

Ra\/en

CEG'er
Joined
Oct 13, 2003
Messages
34
Location
Notre Dame, IN
I know I just posted a question not long ago but that was for my Mystique.
Anyways, this question is about my 1999 cougar. Same setup as my Mystique. Is it possible for a vacuum leak to cause the engine to misfire while driving it. The car has a very bad idle, where I have to give it some gas to keep it from dying. Once I do this, the car smooths out while in Park. Then I try to drive it and the idle is terrible. As I was driving I felt the car surge forward and that is when I got a misfire blinking CEL. I am taking the car to a shop but I want to be sure that a vacuum leak could cause the misfire, because I don't want them to read the codes from the car and automatically think that it is the plugs and wires.

Thanks and sorry in advance if this has been covered before.
 
....but I want to be sure that a vacuum leak could cause the misfire, because I don't want them to read the codes from the car and automatically think that it is the plugs and wires.
....
The answer is yes. Especially if it is in the intake manifold (after the MAF sensor) or EGR area. I know. :eek:

I had a P0174 and P303 recently. I need to change my EGR gasket (when it gets to 40 and rising) maybe next month :blackeye: .
 
Back
Top