[Darkside323]

Hi everyone!!! Great forum. I come from the Mustang world but since my wife brought in the 2014 528i into our family I have been finding a lot of great tips on here.

Here is my current story that I could use some advice on. Sooooo....
Recently the car went into Drivetrain Malfunction mode but still made it home no problem. The issue ended up being the High Pressure Fuel Pump so I replaced it. Everything seemed fine and strong for about a week. All of a sudden while cruising on the Freeway the car went into DMM again but this time it was misfiring, along with a strong smell of gas. Car still made it home. I hooked up my FOX scanner and it came out with codes P0304 and P0300. After some research I figured coils or plugs so I changed both on all 4 Cylinders. I reconnected the battery, cleared the codes, and started the car up. Unfortunately the problem and codes still came back and it seemed like the smell of gas was more prominent.
I'm thinking that the Fuel Injector in number 4 has gone bad. What do you all think? Any other ideas?
Thanks in advance!!!

[AZ-MCRacer]

If you are smelling gas inside the car I'd pull your rear seat and check your LPFP, make sure nothing is broken there and you still have a good tank seal.

[Darkside323]

Thanks for the response. I should have been clearer. The smell of fuel is more prominent in the engine bay and the exhaust is also putting out its own special odor. The exhaust smell makes sense because of the misfire and fuel being shut off to the cylinders. But the engine bay odor leads me to believe the fuel injector on #4 is bad since the initial misfire occurred in cylinder #4.
I will check out the LPFP though.
Side question for you all - Does the misfire in #4 P0304 lead to the P0300???

[Darkside323]

Any tips????

[Darkside323]

I will also add that the car has never had any engine mods.

[BurrNinja]

Originally Posted by Darkside323

I will also add that the car has never had any engine mods.

Possible injector issues. Are the fittings on the fuel lines tight up to the injectors?

[Darkside323]

Thanks for the reply!!! Yes all fuel fittings are tight and no leaks are present.

[Darkside323]

Could these issues be related to something else in the fuel delivery system?

[Darkside323]

I ended up ordering a fuel injector from FCP Euro and a puller from Amazon. I will post updates once installed.

[khanmohammed]

Originally Posted by Darkside323

Hi everyone!!! Great forum. I come from the Mustang world but since my wife brought in the 2014 528i into our family I have been finding a lot of great tips on here.

Here is my current story that I could use some advice on. Sooooo....
Recently the car went into Drivetrain Malfunction mode but still made it home no problem. The issue ended up being the High Pressure Fuel Pump so I replaced it. Everything seemed fine and strong for about a week. All of a sudden while cruising on the Freeway the car went into DMM again but this time it was misfiring, along with a strong smell of gas. Car still made it home. I hooked up my FOX scanner and it came out with codes P0304 and P0300. After some research I figured coils or plugs so I changed both on all 4 Cylinders. I reconnected the battery, cleared the codes, and started the car up. Unfortunately the problem and codes still came back and it seemed like the smell of gas was more prominent.
I'm thinking that the Fuel Injector in number 4 has gone bad. What do you all think? Any other ideas?
Thanks in advance!!!

Might sound dumb, but that also happens from mixing high octane and low octane gas in one tank. Or even diesel and gasoline

[Darkside323]

Hi!!! Offering help is never dumb. But yeah the fuel has always been just fuel. Thanks for the response.

[kennf10]

its the vacuum pump need a change. did mine awhile ago. had the same problem as yours.

[Darkside323]

Thanks for all the feedback!!!! Update!!! So my problem ending up being Fuel Injector #4. After installation and coding with the trusty FoxWell510. All was well. Recently though I got yet another Check Engine Light along with Code 180001 “Catalytic Converter efficiency Limit Below limit value. I cleared it once hoping it was a glitch but it came back after a couple of weeks. This car is definitely getting on my nerves!!! So does this mean I need a new Cat or could it be an O2 sensor? Any ideas???

[Boosted M5]

Misfires are cat killers. You can try the O2 but it may be too late.

[Darkside323]

Originally Posted by Boosted M5

Misfires are cat killers. You can try the O2 but it may be too late.

Thanks for the reply. That's what I'm thinking too!!!

[Darkside323]

Where is the least expensive place to get a replacement Cat?

[Boosted M5]

Forum or junk yard