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

830

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

830

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

1 people found this helpful.
67,965

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.

830

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.

830

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.

67,965

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.

1 people found this helpful.
830

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...

830

No problem.

13,005

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 30,947 nationwide Jetta listings starting at $1,100.

ZIP:

Volkswagen Jetta Experts

  • #1
    Goodwrench707
    Reputation
    2,760
  • #2
    Deathjam4
    Reputation
    2,390
  • #3
    Scott Sr.
    Reputation
    1,550
View All

Related Models For Sale

Used Volkswagen Passat
418 Great Deals out of 21,175 listings starting at $1,100
Used Honda Civic
533 Great Deals out of 40,434 listings starting at $1,699
Used Volkswagen GTI
97 Great Deals out of 5,253 listings starting at $1,000
Used Honda Accord
719 Great Deals out of 96,716 listings starting at $1,225
Used Volkswagen Golf
66 Great Deals out of 4,613 listings starting at $1,900
Used Toyota Camry
1,012 Great Deals out of 70,645 listings starting at $1,137
Used Toyota Corolla
680 Great Deals out of 60,136 listings starting at $1,400
Used Audi A4
161 Great Deals out of 8,719 listings starting at $1,900
Used BMW 3 Series
936 Great Deals out of 29,781 listings starting at $950
Used Chevrolet Cruze
486 Great Deals out of 62,165 listings starting at $2,988
Used Nissan Altima
912 Great Deals out of 54,141 listings starting at $1,300
Used Mazda MAZDA3
272 Great Deals out of 23,373 listings starting at $100
Used Volkswagen Tiguan
208 Great Deals out of 18,057 listings starting at $4,000
Used Volkswagen CC
61 Great Deals out of 1,947 listings starting at $3,495
Used Hyundai Elantra
462 Great Deals out of 46,647 listings starting at $1,399

Used Cars For Sale

2015 Volkswagen Jetta S For Sale
36 Great Deals out of 1,158 listings starting at $6,497

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.