P0304 engine lights (cylinder 4 misfire)

Asked by Jun 04, 2017 at 03:51 PM about the 2011 Volkswagen Jetta S

Question type: Maintenance & Repair

P0304 errors for cylinder 4 misfires. dealership replaces spark plugs. 4000 miles later same error and replaces fuel injector in less than 20 minutes. 5 miles later Jetta gets towed to dealership with P0304 and EPC engine lights on. replaces ignition coil and wire set.
dealership insists that it's just a big coincidence that the coil failed immediately following their injector replacement. according to the dealership it's impossible that they caused it. just wondering if that is true? Thanks.

11 Answers

540

So was #4 ignition coil replaced with spark plugs the first time. There was probably nothing wrong with the injector. The ignition coil was faulty. Rarely ever see injectors fail. If they got you to do an induction cleaning when you had the spark plugs replaced. That would have caused the injector to fail.

they replaced spark plugs only on 1st repair. didn't see anything about induction cleaning... at 2nd visit, i stated that based on error the wires/coil should be replaced, but they said that they will check on their own and replaced the injector instead. only to return 5 miles later

540

They replaced injector for no reason. Knowing a p0304 represents specific cylinder that is misfiring.

52,725

Since we were not present when the diagnosis and repair was done all we can do is assume. We all know what happens when we assume. Get it fixed and let it go and move on.

540

I understand that. If it was an injector. It would have set a p0300 for random and if there was a problem with the injector. A p0204 would have set for open inj driver or short to ground. Anybody knows that's a technician. If the misfire is cylinder specific. The computer is going to name that cylinder. P0304. I don't assume.

540

I know what happens when we assume. That gentleman was charged for an injector he didn't need. If I assumed like you claim. I would have to close shop.

52,725

Not necessarily. I have seen a P0308 normally suspected to be plug, coil or related wiring actually be a faulty injector. You certainly assumed here as I am pretty darned sure you were not present at the shop during this car's diagnostic testing.

540

Again I didn't. There would be other codes associated with that code. Random misfire, lean condition, base timing exceeded minimal threshold.

thanks for your help. clearly, the dealership got one over on me...

540

No problem.

10,625

when you take your car to the dealer you really need to stay on top of them. I had a power steering pump blow off all its pump fins due to frozen fluid in my pump during the winter. took me 5 times of driving to the dealer to get it fixed. they kept telling me its normal when i knew for a fact that the car steered like a dream a month before the cold weather happened. The dealer always trys to screw you and charge you for more then you really need. If its warrenty work take it to the dealer other wise find a good VW/Audi specialist to look at the car it will be cheaper and done right the first time not a little here a little there.

Your Answer

Jetta

Looking for a Used Jetta in your area?

CarGurus has 35,189 nationwide Jetta listings starting at $1,400.

ZIP:

Volkswagen Jetta Experts

  • #1
    Goodwrench707
    Reputation
    2,460
  • #2
    Deathjam4
    Reputation
    1,950
  • #3
    Scott Sr.
    Reputation
    1,470
View All

Related Models For Sale

Used Volkswagen Passat
355 Great Deals out of 20,151 listings starting at $995
Used Honda Civic
742 Great Deals out of 68,804 listings starting at $1,350
Used Volkswagen GTI
137 Great Deals out of 7,957 listings starting at $2,100
Used Honda Accord
963 Great Deals out of 59,155 listings starting at $1,099
Used Volkswagen Golf
109 Great Deals out of 4,789 listings starting at $2,450
Used BMW 3 Series
1,051 Great Deals out of 33,474 listings starting at $1,000
Used Toyota Camry
880 Great Deals out of 81,517 listings starting at $999
Used Toyota Corolla
752 Great Deals out of 54,183 listings starting at $1,500
Used Audi A4
265 Great Deals out of 11,874 listings starting at $199
Used Nissan Altima
963 Great Deals out of 77,818 listings starting at $1,695
Used Volkswagen CC
72 Great Deals out of 2,785 listings starting at $3,300
Used Mazda MAZDA3
329 Great Deals out of 26,080 listings starting at $950
Used Chevrolet Cruze
882 Great Deals out of 57,191 listings starting at $2,795
Used Volkswagen Beetle
165 Great Deals out of 7,557 listings starting at $1,250
Used Ford Focus
754 Great Deals out of 54,998 listings starting at $800

Used Cars For Sale

2017 Volkswagen Jetta S For Sale
12 Great Deals out of 5,124 listings starting at $10,517
2015 Volkswagen Jetta S For Sale
25 Great Deals out of 626 listings starting at $6,990
2014 Volkswagen Jetta S For Sale
46 Great Deals out of 1,236 listings starting at $5,988
2013 Volkswagen Jetta S For Sale
10 Great Deals out of 203 listings starting at $4,999

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.