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Discussion Starter · #1 ·
Hi

While driving my car this morning, the vehicle started to buck and shake very ruff, I slowed down and my check engine light started blinking. I shut the car off and pulled to the side of the road. I started the car back up and started driving again, the check engine light came back on and stayed light. The car starts the buck when the boost hits 6 PSI.

The codes that where read are below:

P0300 General misfire code
P0303 The PCM has determined that a misfire has occurred in cylinder #3
P0304 The PCM has determined that a misfire has occurred in cylinder #4

Any ideas on what this could be, I tried searching but found posts that don’t really trouble shoot my problem, my car runs fine but has soon as the boost level rises above 6 psi the car immediately starts to buck very hard. Is there something wrong with the N75 valve, or is this something ICM related, because of the misfire codes. Help is greatly appreciated.

Thanks

GO PATS!
 

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2001 Passat wagon; 2016 Golf Sportwagen
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Swap #1 and #4 coilpacks, clear the codes, and then see whether the problem remains on #3 and #4 or is now on #3 and #1.
 

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Discussion Starter · #8 ·
Twomanypassats

The ICM is sensor that is located in the airbox, with the heatsink on the opposite side? If so I relpaced it about a month ago, the check engine light was constantly flashing and the car ran like crap. Is it possible that the ICM went again? I am going to switch the coil packs from 1 to 4 and see if I get the misfire on #1. Its weird the car runs and drives fine up until 5 psi, when the boost level reaches above 5 psi the car starts to buck very hard.
 

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One more time, and I'm outta here
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I have the following codes...

PO300 General misfire code
PO303 Cylinder 3 misfire
PO171 System too lean

I have the same effects (car shudders, but mine is at an idle) and the CEL flashes from time to time. I cleared my codes and they have not come back. However I know there is an effect with the boost and a system too lean most likely is related to increased air flow or too much from a torn line.

I believe mine is related to a torn vaccume line.
 

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Twomanypassats

The ICM is sensor that is located in the airbox, with the heatsink on the opposite side? If so I relpaced it about a month ago, the check engine light was constantly flashing and the car ran like crap. Is it possible that the ICM went again? I am going to switch the coil packs from 1 to 4 and see if I get the misfire on #1. Its weird the car runs and drives fine up until 5 psi, when the boost level reaches above 5 psi the car starts to buck very hard.
Anything is possible. A misfire will make the CEL flash and the car run like crap. What causes the misfire is what you need to find. On the five pin side of the ICM, check continuity to the other four pins from the third pin. If it needs replacement, use the Huco, not the Bosch.
 

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Discussion Starter · #11 ·
So, I just got my coilpacks in and installed. I still have the same exact problem. I have no idea what to check now, I replaced coils on cyl 3 & 4, the ICM was replaced last month, what else controls the firing of the coils? The help is greatly appreciated.

Thanks

Jimmy
 

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I had a similar problem over a year ago (misfire in 2 cylinders) and it ended up being the cables. One they got replaced the problem went away. Also what about the sparkplugs?
 

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Discussion Starter · #13 ·
I put new spark plugs in when I bought the car, so I have put about 40,000 on the plugs I think they should still be fine? Also How do I change the wires connecting the the coil packs?

Thanks
 
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