CHECK ENGINE LIGHT IS ON
 

2003 X5 3.01 AWD
Check engine light is on.
I have replaced my DISA valve and also replaced the MAF.
Spark plugs are new, air filter is new, Fuel filter is new.
I am getting code P0175 Bank 1 System too lean
P0172 Bank 1 System too lean.
Any cluese what is causing these codes?

Most common cause is likely a cracked lower intake boot, but there are plenty of vacuum leak problem areas on these engines. Also be prepared to replace the CCV and hoses as well.

Smoke test is the quickest and easiest way to find the problem(s). Make sure you check both the intake and crankcase. Remove the oil fill cap and let the crankcase fill with smoke then put the cap back on.

See this video below, cheap fluid transfer pump under $10 at most auto parts stores, a few rubber gloves, rubber bands and cheap cigars.

https://www.youtube.com/watch?v=AsgB9eBl58I

As noted before smoke test is the best way to determine a leak that is producing a lean code.

Forgot to mention, keep your original MAF if you still have it. I would put it back on the vehicle.

Unless you purchased a Siemens/VDO MAF from a reliable source, if what you purchased was a no name or too cheap to be true, chances are it is an Asian counterfeit that may make matters worse.

I NEVER throw away a MAF, but I also rarely change them either. MAF's are replaced far too often when they are good. Unless you have Lean codes at highway cruise, chances are the original MAF was fine.

No code expert, but why not find a good Indie with good scanner/BMW menus and have him read your code(s)?

I had P0172, AZ read it generically, and then a good local Indie nailed it via a specific menu/sub menu and replaced the exhaust camshaft sensor...

Rather than throwing parts, fiddling with MAF/DISA, get it read and then chase the part(s) repair.
GL, mD

POINT OF ORDER
Lean codes are P0171 & P0174. The codes you gave are for Rich, not Lean.

P0170 & P0173 are Malfunction
P0171 & P0174 are Lean
P0172 & P0175 are Rich

Since there are specific codes for lean and rich, I assume that "malfunction," means that the fuel trim/control swings between rich and lean -- it is unstable enough to be wrong, but not consistently wrong to be one or the other.

Thanks for the input. You got it all wrong here. DISA and MAF was already replaced. Not because of this issue.

Miswrote...your orig post read like you had changed out MAF, et al, in the pursuit of extinguishing the CEL.

My thought was/is get the code(s) read with a real code reader with proper interpretation, and with that diagnosis an effective repair can be made.

Despite the misunderstanding, his advice to have the specific BMW codes read would be a great place to start. Those codes are thrown by so many causes... MAF, DISA, O2 sensors, CPS, vacuum leaks (most common), CCV, etc, etc.

If the SES/CEL/MIL is lit you really do not need a BMW specialized tool or software to read the codes.

OP did not mention what tool was used to read the codes and did not provide Freeze Frame date or Fuel Trim info.

Yes, in theory P0172/P0175 tend to be Rich codes, HOWEVER, there may be some typos and even if you study the Bentley manual closely there are some BWM codes that at least Bentley show pr translaste as BOTH Lean and Rich codes.

So I would guess the tool originally used likely output the codes in BMW 3 digit format and were incorrectly translated. Most modern vehicles do not run Rich as the vehicles ages and sensors and components age, usually the opposite.

I would be more than comfortable using a decent generic OBDII tool to gather the codes from this vehicle along with Freeze Frame and Fuel Trim data. Even a smart phone App like OBDFusion would be more than adequate to start with and it will give correct info because there is no translation from a BMW specialized code, the tool reads the OBDII PID's directly.

That's all good and I'm sure your way works. How ever plugging in some BMW software would most likely take you right to the root cause instead of logging data and freezing this and that. Seems that's all I read about lately. When my cam sensor went out I used an Obd reader and it didn't tell me I needed a cam sensor. I googled and started a thread and someone said it might be a cam sensor. I plug in INPA and it flat out told me I need a new cam sensor.

If the op would have had the code read via some sort of BMW software, this thread would have never been started, and he would have more money in his pocket!

It does not quite work the way you think it does. OBDII supports cam sensor error codes as well as many other. Regardless of what tool/software is used, there is rarely any clear cut thing that says "replace this part and your problem will be solved". All any code is a "clue", there was some logic statement that something was outside of a parameter threshold to allow the code/error to trigger. The is no specific magic about any tool whether a generic OBDII App or a $50k dealer tool. At the end of the day, ALL information needs to considered and it will be an educated guess/decision as to what the next step may be.

The M54 is a vacuum leak waiting to happen and if I had to guess the OP has one or more vacuum leaks on his 13-14 year old vehicle.

As I mentioned it will be highly unlikely that the OP actually has a Rich condition, most Rich conditions, if they exist are false positives.

For future reference an easy way to test a MAF is to unplug it. If it runs worse and stalls the MAF is fine

I'm getting the same 2 rich error codes using a standard OBDII on my '02 3.0. Yes, taking it to the dealer or indie shop is one solution but I'm trying to figure it out and fix it myself so that's not really helpful advise, more of a Captain Obvious response and not what a forum is about IMHO.

Doubtful its a vacuum leak as that is a lean situation not rich. If anyone is getting these error codes with a standard reader and have found a cause, please share!

What OBDII tool are you using??

Suggest you post Freeze Frame and warm idle Fuel Trim info before you do anything else.

The engine may be running Rich but I doubt it, most "Rich" conditions are false positives. Also the code(s) may have been translated incorrectly.

Post exact codes and the OBDII tool you are using.

AutoXray CodeScout AX2500

Exact codes are P0172 and P0175

I found a thread here: http://www.xoutpost.com/bmw-sav-foru...0175-dtcs.html that looks promising so following that guidance to check for leaks in the intake bellows next.

You are a new member here, you have 2 threads you are working for the same problem.

You need to determine what thread you want to proceed in with this problem.

Also I hate to tell you, the current scan tool you have is not likely going to be a lot of help. Unclear if it supports Live/Realtime data and you have to buy software to transfer info to a PC.

Spend less than $30 for the OBDFusion App and interface. This will run on your phone/tablet and will allow you to gather a great deal of data and post it for review and comment. There is not way you will be able to easily transfer the large amount of data from your current tool, much less Log OBDII PID data. Trust me, this is not my first rodeo and OBDFusion is worth every penny of $10 or less for the App. Yes you have to figure it out, but most people can get the hang of the tool within the first 10-20 minutes playing around with it.

You can chase some of the ideas you have based on this forum, but here is most of what you really need to know:

Cold weather misfires and CEL, common issues $50 fix! - E46Fanatics

OBD Fusion, How to Log Data, courtesy of jfoj - E46Fanatics

Idle sputtering, intake popping, CEL, and exhaust smells like gas - E46Fanatics

Yes, I am a new member here. ?? No, I am not new to forums but this is my 1st X5. You can check the E28 forum, E10 forum on Roadfly, Volvo forums, and Jeep Wrangler forums if you'd like to continue your investigation.

Yes, I have a thread going to try and solve my issue but did a search on the topic again and came across this thread that I posted to - That's how forums work. I will 'proceed' with my other thread but will read through the links below you have provided so thanks for that.

Solution for this issue found
 

After driving with a check engine light on for one year, I finally fixed it.
It turned out back in 2015 I changed the fuel filter and used a Mahle filter I bought on Amazon for around $50 or so.
Last Saturday I replaced the fuel filter once again, now I used an OEM BMW filter I bought at Pelican parts for $107.
I reset my check engine light , it is now gone.
I think the problem was the in filter pressure regulator for non OEM does not have the correct fuel pressure, hence check engine light was on showing codes P0172 and P0175.
P.S
The OEM BMW fuel filter also says Mahle on it , but also has a BMW Logo on it.

Perhaps you just had a defective Mahle fuel filter from amazon.

Seems like a logical cause-and-effect there, but I highly doubt the filter 'spec' is any different. I'd be looking for the SES to come back on.

Wrong.
Before when I reset the light it would come on the same day. After I replaced the fuel filter with OEM one, its been now 900 miles no check engine light anymore :bmw: