P0302 error code

[samguan]

So it looks like cylinder 2 is misfiring, I have about 60K miles on 2009 GTI, I bought it used at 44K. Never changed any spark plugs or coils since I bought it and don't know if the previous owner did or not.

Couple months back, one morning when I started my car, the CEL light flashed for couple seconds and it was gone. The computer didn't store any code everything ran perfectly.

Recently, I've been noticing during morning start idle, the exhaust note is not very smooth, takes about 15 seconds to settle down. The engine feels fine, no vibration or power loss or anything.

Just 30 minutes ago when I started my car, the engine light flashed for couple seconds and stayed on. I used my ODB2 reader and it read P0302. I didn't drive the car but the engine runs fine, no vibration or anything. My gf recently had a misfire on her BMW and the engine is rough at idle but mine doesn't do that.

Any suggestions what I should do next?

Should I change the spark plug or the coil or both?

Update: This problem has became more worse to the point of excessive vibration during cold start and flashing CEL on every cold start. Finally found a solution.

 

[Mr Lime v2]

Very similar situation. I have a cylinder two misfire in my car too. I'm at 72k and bought mine at 45. I changed all the spark plugs last night and had a misfire on my way to work this morning when I stepped on it but when I stepped on it again it was fine. When I removed the spark plugs from the engine, one of them had oil on it. The others were good other than being a little dirty. If the plugs aren't fixing it then I might swap coil packs too.

Edit: only difference is I'm FSI.

Sent from my SCH-I535 using Tapatalk 2

 

[samguan]

Just bought one ignition coil from the local dealer, cost a little over $50 after tax. Shipping really kills a lot of good prices for Canadians! ECS has 4 for $80 something.

 

[samguan]

Hopefully it will fix the problem, will report back soon!

 

[samguan]

Ok I replaced the ignition coil and reset the light. Have driven 50KMs today and no lights have shown up.

However, I had a really hard time disconnect the coil from the connector. The tabs were really right and I ended up breaking one of the tabs. I had to use a right angle pick tool which put a little damage to the connector.

 

[samguan]

Felt like those connectors are really hard to remove, saw a video on YouTube this guy just pushes down on the tabs and came off easily. Mine wasn't like that at all. Removing the actual coil was super easy.

Any suggestions on removing those connectors in the future? I might also have to buy the connector housing to fix the one with the broken tab.

 

[samguan]

so the light came back on, I'm going to try and change the plug as well.

With this code, does it mean it's constantly misfiring?? When I plugged in the OBD2 reader, it has records, one is a freeze frame??

 

[fierce bad]

"So it looks like cylinder 2 is misfiring, I have about 60K miles on 2009 GTI, I bought it used at 44K. Never changed any spark plugs or coils since I bought it and don't know if the previous owner did or not."

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The recommended interval for changing the plugs is 60k miles. You should change all four plugs just as routine service. If you bought the car before it had 60k miles, it was most likely NOT done by the previous owner. Replacing all four coil packs is not required, but some people recommend it as well (mostly people who sell coil packs ).

 

[samguan]

The problem is no longer what I described in my first post, it's has turned into active misfiring(vibration) and flashing CEL on every cold start. It would still settle down after a minute or so.

After $1000, the car finally runs fine.

Got 4 new plugs and coils and it didn't help. Still misfiring during idle and clears after a minute.

Took it to a shop(recommended by the forum people) and was told it had carbon buildup and the injectors weren't in great shape. After cleaning them, they looked alright but still not as good as new. Since the intake manifold is already out, why not just swap all 4 injectors. If the injectors were the cause and I didn't change them, then I would have to have them take out the manifold again which takes time.

After hours of clearing the carbon and putting in 4 new injectors. The car cold starts and idles perfectly now.

With these issues, you really just have to eliminate potential causes. From plugs to injectors and to carbon buildup.

In conclusion, I think the misfire is caused by the carbon build up because the injector #2 didn't look as bad as the other cylinders that are firing fine.

Like I said, the rough idle started many months ago and it got worse over time so something is building up or failing.

 

[freshpots]

The problem is no longer what I described in my first post, it's has turned into active misfiring(vibration) and flashing CEL on every cold start. It would still settle down after a minute or so.

After $1000, the car finally runs fine.

Got 4 new plugs and coils and it didn't help. Still misfiring during idle and clears after a minute.

Took it to a shop(recommended by the forum people) and was told it had carbon buildup and the injectors weren't in great shape. After cleaning them, they looked alright but still not as good as new. Since the intake manifold is already out, why not just swap all 4 injectors. If the injectors were the cause and I didn't change them, then I would have to have them take out the manifold again which takes time.

After hours of clearing the carbon and putting in 4 new injectors. The car cold starts and idles perfectly now.

With these issues, you really just have to eliminate potential causes. From plugs to injectors and to carbon buildup.

In conclusion, I think the misfire is caused by the carbon build up because the injector #2 didn't look as bad as the other cylinders that are firing fine.

Like I said, the rough idle started many months ago and it got worse over time so something is building up or failing.

It's quite rare for injectors to be the culprit.. My car has 65k miles on it and I'm sure it could use a good valve cleaning, but my car runs buttery smooth and gets only slightly below average fuel economy. Sucks big time dude, that's a hefty bill.

 

[samguan]

the injectors look alright after cleaning them. I just wanted get it fix, I didn't want to just do the valve cleaning and put it back and it turns out it's the injector. I should have just replace that one injector but if I'm going to pay them labor to take the manifold out, I might as well put new injectors in and not have to touch them at least for now.

 

[razr]

Atleast now you know is firing like new.

 

[samguan]

Ok, I noticed a small issue now. When my car is stopped at a traffic light for 10 seconds or so... Car starts to shake a little and could hear a little popping from the exhaust. Every 7 seconds or so, the engine would shake once if I see it from the hood.

Does it sound like some kind of air leak?