# P0304 code



## Bthasht (Oct 6, 2011)

Check engine light flashes then stays on. Epc light stays on 
Car shakes pretty bad. Bad smell or odor. Hard to start without putting had pedal to floor.
Code scan says cylinder 4 misfire.

You guys got any ideas?

Sent from my SGH-T999 using Tapatalk 2


----------



## sk8too (Dec 23, 2004)

Have you check to make sure your plug wires are still on there tight? I've seen wires just come loose before.


----------



## MikeinNJ (May 9, 2007)

Bthasht said:


> Check engine light flashes then stays on. Epc light stays on
> Car shakes pretty bad. Bad smell or odor. Hard to start without putting had pedal to floor.
> Code scan says cylinder 4 misfire.
> 
> ...


My car JUST did the same thing again a few minutes ago on my way into work. I have a tune and I'm about 95% sure that it is due to my coil packs.

The car is going into 'limp' mode and deactivating the cylinder. This can also happen to folks without a tune where the coil packs just go bad. 

Are you tuned? Most like it is due to bad coil packs. I already ordered the red top R8 replacements: http://www.deutscheautoparts.com/vw_product.aspx?pid=267872&id=2553

More info here:
http://www.golfmk6.com/forums/showthread.php?t=53930


----------



## Bthasht (Oct 6, 2011)

sk8too said:


> Have you check to make sure your plug wires are still on there tight? I've seen wires just come loose before.


I checked the connections to the coil packs last night. No problems there.



MikeinNJ said:


> My car JUST did the same thing again a few minutes ago on my way into work. I have a tune and I'm about 95% sure that it is due to my coil packs.
> 
> The car is going into 'limp' mode and deactivating the cylinder. This can also happen to folks without a tune where the coil packs just go bad.
> 
> ...


Yes my car is unitronic tuned. I have the red top coils from ecs already. They have only been on about two months. Was going to check them after work for sure though.

Any other thoughts?

Sent from my SGH-T999 using Tapatalk 2


----------



## MikeinNJ (May 9, 2007)

Check spark plugs. Make sure they are gapped to .028 and maybe upgrade to the NGK Iridiums if you haven't already done so.


----------



## MikeinNJ (May 9, 2007)

Also, you can remove your PCV and see which valve springs you have. Depending on the color stripe on the springs, you may have weak springs. This usually only matters if you are Stage 2-3.

http://www.golfmk6.com/forums/showthread.php?t=50417

They say the weak springs have only shown up on 12/13 models, but if you go through that thread, they have shown up in nearly all years of TSI models to some extent.


----------



## Bthasht (Oct 6, 2011)

MikeinNJ said:


> Check spark plugs. Make sure they are gapped to .028 and maybe upgrade to the NGK Iridiums if you haven't already done so.


My plugs arengk iridium also from ecs same time as coils. I will check gap as well though just in case.




MikeinNJ said:


> Also, you can remove your PCV and see which valve springs you have. Depending on the color stripe on the springs, you may have weak springs. This usually only matters if you are Stage 2-3.
> 
> http://www.golfmk6.com/forums/showthread.php?t=50417
> 
> They say the weak springs have only shown up on 12/13 models, but if you go through that thread, they have shown up in nearly all years of TSI models to some extent.


Mine is stage 1+ for now, but been thinking about stage two.

Awesome checks. Ill look into that thread as well. Thanks

Sent from my SGH-T999 using Tapatalk 2


----------



## njm23 (May 30, 2008)

Bthasht said:


> Check engine light flashes then stays on. Epc light stays on
> Car shakes pretty bad. Bad smell or odor. Hard to start without putting had pedal to floor.
> Code scan says cylinder 4 misfire.
> 
> ...


You have a few options.. Since it is narrowed down to JUST cynlinder 4.

1) swap coil packs from cylinder 1-3 with cylinder 4. See if the misfire follows that coil pack.
2) injector stuck open
3) plug is bad (prob the least chance out of the group here)


----------



## Bthasht (Oct 6, 2011)

njm23 said:


> You have a few options.. Since it is narrowed down to JUST cynlinder 4.
> 
> 1) swap coil packs from cylinder 1-3 with cylinder 4. See if the misfire follows that coil pack.
> 2) injector stuck open
> 3) plug is bad (prob the least chance out of the group here)


I'm going to swap coils when I get off. A good vw kid always has extras laying around:thumbup: the injector was my first thought due to the smell and very quick has consumption

Sent from my SGH-T999 using Tapatalk 2


----------



## S WORD (Jul 21, 2011)

Sounds like stuck open injector my friend.
This just happened to me last week after leaving mechanic after getting intake manifold replaced and valves cleaned.

I had a random P0301 last night for first time when doing a full throttle pull on freeway. Car ran like crap but I had just put on new air filter and think it was not sealed completely. I believe a small vacuum leak make cause misfires. Did you work on anything in the air system recently?


----------



## Bthasht (Oct 6, 2011)

S WORD said:


> Sounds like stuck open injector my friend.
> This just happened to me last week after leaving mechanic after getting intake manifold replaced and valves cleaned.
> 
> I had a random P0301 last night for first time when doing a full throttle pull on freeway. Car ran like crap but I had just put on new air filter and think it was not sealed completely. I believe a small vacuum leak make cause misfires. Did you work on anything in the air system recently?


I replaced intake manifold, coil packs, and plugs about a month and a half ago. I'm thinking injector myself

Sent from my SGH-T999 using Tapatalk 2


----------



## Bthasht (Oct 6, 2011)

Well swapped coils and check plugs. Not the problem. Still p0304 cylinder 4 misfire. Car would not start without putting gas pedal to floor. Then blew crazy white smoke once it did start. Smelled like fuel bad. Guess I gotta pull manifold and replace injector?

Sent from my SGH-T999 using Tapatalk 2


----------



## njm23 (May 30, 2008)

Bthasht said:


> Well swapped coils and check plugs. Not the problem. Still p0304 cylinder 4 misfire. Car would not start without putting gas pedal to floor. Then blew crazy white smoke once it did start. Smelled like fuel bad. Guess I gotta pull manifold and replace injector?
> 
> Sent from my SGH-T999 using Tapatalk 2


I'd bet some money on it. I've never done it, can't imagine it's all that difficult, I just don't know if the system needs to have the pressure released or not.


----------



## Jaeycee (Apr 6, 2021)

I’m going through the same thing and it’s killing me man I’ve swapped everything already and still can’t get rid of the code even ran a compression test and everything turned out good, has anyone cleared it?


----------



## OEMplusCC (Jan 27, 2013)

Jaeycee said:


> I’m going through the same thing and it’s killing me man I’ve swapped everything already and still can’t get rid of the code even ran a compression test and everything turned out good, has anyone cleared it?


What is everything? Spark plugs and coils? 
Have you confirmed its not a bad injector?

When was the last time you had carbon cleaning done? That can also cause this.

air leak can cause this as well. Make sure your rear main seal is not leaking. See if there is oil wetness between transmission and the engine from the bottom.

Sent from my Nokia 6.1 using Tapatalk


----------



## Jaeycee (Apr 6, 2021)

OEMplusCC said:


> What is everything? Spark plugs and coils?
> Have you confirmed its not a bad injector?
> 
> When was the last time you had carbon cleaning done? That can also cause this.
> ...


I’ve replaced my spark plugs coils and injectors and for some reason I’m getting fuel on cylinder 4 that’s wetting my plug


----------



## OEMplusCC (Jan 27, 2013)

Jaeycee said:


> I’ve replaced my spark plugs coils and injectors and for some reason I’m getting fuel on cylinder 4 that’s wetting my plug


Thats indication of a bad fuel injector. Did you buy new injectors? And were they OEM or at least OE Bosch injectors? 
I don't trust anything you can buy from brick and mortar stores

There is a 8pin fuel injector connector under the right side of the intake manifold. Unplug it and measure resistance on each pair of pins for each injector. Resistance should read something small I believe around 4ohms but i might be wrong. If resistance is very high or infinity that indicates stuck open injector

Sent from my Nokia 6.1 using Tapatalk


----------

