Misfiring

2005 FORD MUSTANG
180,000 MILES • 4.0L • V6 • 2WD • MANUAL
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KIMBERLY HANSEN
  • MEMBER
  • 4 POSTS
Every time I drive the car it sputters in 1st, 2nd, and 3rd gear. When I put it on the computer it said to change my EGR valve and so I did and it still does the same thing. It seems like it misfires. I changed the spark plug wires but it didn't fix it. What else could it be?
Aug 26, 2021 at 11:37 PM
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MASTER ASE TECH
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 82 POSTS
Hi, I'm Dan.

Misfires can be tracked down by eliminating things one at a time. Could be spark, fuel, vale related, or compression. Please see the attached articles to see if you can eliminate a couple things. I always try the easy things like spark plugs and such first.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

In addition to this being a misfire, it could just be a fuel shortage causing a rough running condition. So not only do we need to check the spark plugs but we need to check the fuel pressure as well.

Here is a guide that will help with this.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Lastly can you remove the plugs and take a look at them to see if they are worn or showing signs of an issue. I am attaching a chart below that will show what they look like and the possible cause.

Please take a look at them and let us know which one they look closest too. Or just get a couple pictures of the plugs and we will be able to figure out next steps.

Thanks
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Aug 27, 2021 at 10:43 AM
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