I know that this topic has been discussed in the past and increased emissions can be caused by multiple items. I have an INPA cable ordered so that I can monitor adaptions and learn to monitor and program my E60.

Anyway, my OBD2 cable gave me a P0174 stored error and P0171 & P0174 pending errors. I have attached some photos of what EasyOBD showed. It looks like the P0174 error was thrown when I was not even moving the car - 0 mph. The short term fuel trims were both above 10%. This is the only thing that looks abnormal to me but I am relatively new to this.

Can anybody with experience please give me your input on what you see and what it could be. I have new spark plugs, new air filter, and I have cleaned my MAF sensor twice and still received these errors. From what I can see, my O2 sensors and MAF sensor are just reading what they see.

I know this data is not as good as INPA, but I will have that shortly.

Thank you in advance for any help you can offer!

 

These fault codes usually indicate a vacuum leak. You might want to check to see if there are any vacuum lines off or cracked. Anything that could let in unmetered air.

 

Thanks for the response. I have done a quick check previously and I did not see anything that stuck out to me. I have read that it could be a vacuum leak or a MAF sensor. I think that MAF seems good but I am thinking the same lines you are. It may take a smoke test to find the leak. I am going to do a little more investigating and I may clear the code again just to see.

I somebody online had an intake manifold cap come off. I may check that as well.

 

what is the engine and production year of your car and how many miles on the clock?

 

M54, production year 2004 and approximately 87,000 miles.

 

@moyern83,

did you ever resolve this?

 

jasonkey,

Yes, I did figure the issue out. The main reason that I was getting the errors was that my PCV vent hose was leaking. I have a local Indy shop that does great work, so I took it in to them and they fixed it for what I considered cheap...$108.25.

After I had the hose replaced, I still felt like my garage smelled like gas. I put some BG44K in the tank to clean the fuel system and my Indy also recommended that I only fill up at BMW approved gas stations. It sounds crazy, but after hearing them say it and having it posted on their wall, it makes sense to me.

From that point on, I filled up at only the "BMW approved" gas stations. I never had any issues after that. Attached is a pic I took of what are the "approved."

Moyer

 

My car was in the shop today (thankfully my brother's) for the same faults. Turned out to a bad DISA valve p/n 11617544805. Sprayed with carb clean and nearly stalled the engine. I could definately hear the vacuum leak and the car was idling pretty bad.

 

... and we should drive on 'BMW approved roads' only; otherwise, warranty is void.

 

Hey I've also got the increased emissions warning and its throwing the same p0174 code. Did a smoke test and found no leaks.. what else could it be? My car is an 05 525i 88,000 miles The increased emissions warning has been on for months now so can't be something small like gas cap