Audi A4 B8 code p0303 cel epc light

[Chrisc84]

Hello all, this is my first time posting on Audizine and I'm in seek of a few answers. I have a 2011 a4 b8 audi cvt that I bought last year with 66k miles. I had the stage 2 oil consumption test performed and pretty much got taken care of under warranty with a new turbo, upgraded pistons and rings,timing chain, tensioner and rails. Car hadn't given me any issues since the job was done June 2018.

A few days ago on my way to work I get the epc light and then the cel turns on. I lose power and throttle and get engine vibrations. I pull over and figure I'd turn back home as I had just left my house a few miles ago. This was at 3:30am. I was in no position to park it and try to tow it since I was close to home already. I made it home and turned the car off, tried to turn it on and it wouldn't crank. The cel was flashing at this point. Well I called off work, slept a bit then went to Walmart, bought an obd2 scanner and got a p0303 cylinder 3 misfire. I went on here and looked up possible solutions and pretty much ended up going to autozone and buying all new spark plugs and coils based on fix solutions and suggestions by other members who've also gotten this code.I installed them myself and when I go to turn the car on it was struggling but it cranked and turned on. The idle was a bit rough, exhaust sounded like a diesel and hint of white smoke was barely visible out the exhaust and it smelled like fuel. I immediately turned it off and called a euro specialist shop. They told me they were pretty sure it was the injectors if I smelled fuel but they would need to diagnose. Car gets towed and diagnosed and they recommend all new injectors, carbon clean and new fuel pump. I told them I wouldn't think it needs a fuel pump as there's no code for that coming up. I wasn't in the position to just change the fuel pump unless he knew for a fact it was damaged or faulty. He said it might be the seal that's bad, nonetheless I decided I'd buy new fuel injectors from FCP($211) and have them do the carbon clean and install along with an oil change without the fuel pump. Quote went from $1,600.00 to just $525.00 . I said let's do it. By tomorrow I'll know if everything is Gucci.

I've read about ppl getting the same code, replacing the plugs ,coils, injectors and even carbon cleaning and STILL getting this . In my case there is a smell of fuel, so I'm thinking it's a bad injector, but I'm just gonna do all 4 for peace of mind. Is there something that could trigger p0303 and NOT be any of the reasons above?

Many thanks in advance!

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[JLAllroad]

Your line of thinking is correct...I would believe you had an injector stuck open, hence the smell of fuel and smoke. This is a known occurrence.

If this is the case you will want to change the oil as well due to fuel dilution.

Fuel pumps will go on occasion but it will affect starting, not a misfire in one hole.

How did the spark plugs look?



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[Chrisc84]

That's what I figured, even though the tech made it seem like I was making a wrong decision in not changing the fuel pump. The spark plugs looked pretty dirty and black from the bottom, one looked like it had a bit of oil around the lip of the rim where the thread begins on the plug. I believe it was the 2nd next to the firewal. looked down the plug wells and I felt like they were pretty dirty in there, greasy. seemed to have a bit of grease? at the base of one of the plug wells. The coil packs all looked about equally dirty, looked like little bits of grease smeared on the outer coils, nothing major though. They are also giving the car a fresh oil change though, so hopefully that fixes the fuel in the oil, since the tech did mention they found fuel in the oil filter.

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[JLAllroad]

You may have a leaking valve cover in the spark plugs valleys, a likely source of oil and grime on th he coils and plugs, which these cars love it when you change them...it always runs noticeably better.

Last check would be if the PCV valve was done during the oil consumption fix.


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[Chrisc84]

Ah I see, I will recheck my paperwork from Audi to see if the pcv valve was changed, I can't recall. Thanks a lot for your feedback and suggestions, I really appreciate it. I'll give an update tomorrow when I find out more info on the status of the car

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[Chrisc84]

Update:

Shop called me, told me they pulled the injectors out and found oil all over the injectors. That it was definitely the high pressure fuel pump that needed to be changed, and if I chose to not replace the pump, they wouldn't be able to warrant the work once they pulled my car out and it didn't start. I had no choice but to buy the parts again myself via FCPeuro, overnight them, which still saved me $400 by buying the parts myself instead of going through them, and just paying for labor.

I'm totally thinking of getting rid of the car after the repairs are done

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[JLAllroad]

The fuel pump has nothing to do with oil on the injectors ....what is their explanation.




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[Chrisc84]

That's exactly what I first thought, but this video on YouTube pretty much sums up how my hpfp went bad.

https://youtu.be/VSQea2dXVqE

Looks like my injector is bad but so is my hpfp.

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[JLAllroad]

Idk that he ever deduced that the HPFP was bad as the pressure differences could easily be attributed to the bad injector.

That said, similar to replacing coils and plugs, it will mean the main failure points of the fuel system are addressed.


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[Chrisc84]

Got the car today, took long enough because I chose to order parts myself (saved $375) and get them shipped to the shop. Car runs fine, back to normal, and I got the old parts back as well (injectors/hfpp) Would there be a way to see if the pump is good/bad without having to install it? Just curious.

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