Codes p300 and p302

Tiny
ZTRETTER
  • MEMBER
  • 2003 VOLKSWAGEN PASSAT
  • 1.8L
  • 4 CYL
  • 2WD
  • MANUAL
  • 190,000 MILES
Engine light flashing. Runs rough. Doesn't want to accelerate. Just got a coil and vacuum tee replaced. Ran good until yesterday. Codes p300 and p302 came up as it did the first time. So obviously those have to be replaced again. Is there a deeper issue? Where is the vacuum tee located? Any help would be appreciated.
Saturday, January 11th, 2020 AT 8:27 AM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

Here is what I suggest. Since the coil was already replaced and the same codes came back, I feel there is more to it. As far as the location of a vacuum T, it could be anywhere. Here is a link that explains how to check for vacuum leaks. You can use this to locate a leak:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Is it possible for you to get your hands on a live data scanner? I would really like to know what the short term fuel trims are. I can explain how to get them if needed.

Since the misfire remains at cylinder 2, it could be an injector issue, low compression in that cylinder, fuel pressure, and so on. If possible, remove the spark plug in cylinder 2 and let me know what it looks like. For example, what color is the electrode, is it wet with fuel, and so on. However, before you do that, I suggest checking to make sure there is spark to that plug. Here is a link that explains how to check for spark:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Do these few things and let me know what you find.

Joe
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Saturday, January 11th, 2020 AT 4:53 PM
Tiny
ZTRETTER
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  • 5 POSTS
I switched coils with cylinder 1. No change. I switched plugs with cylinder 3. No change. The plug did look a little wet. Like it had oil or fuel on it. I'm going to check spark to the plug today.
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Sunday, January 12th, 2020 AT 9:59 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,885 POSTS
Hi,

In addition to checking for spark, check compression on that cylinder. Make sure it isn't low. That can cause a misfire as well.

Let me know what you find.

Joe
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Sunday, January 12th, 2020 AT 4:38 PM

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