Z3 1.9 code P0170

[Gilly1]

ANY ONE HAD THIS CODE ON THEIR BMW Z3 1.9 (2000)
THINK IT MEANS FAULT IN FUEL TRIM (BANK 1)
HAVE CHANGED THE FUEL FILLTER BUT STILL GET THE SAME ERROR
WILL CLEAN THE MASS AIR FLOW THIS WEEK END SEE IF THAT WORKS
ANY OTHER SUGGESTIONS PLEASE THANKYOU

 

[billysally208]

Check all hoses for air leaks - run engine with bonnet open and listen for any 'sucking / hissing noises'

 

[zedonist]

A P0170 is generally an air intake leak or vacuum leak, key culprits are all air intake boots and vacuum hoses, just look at all of them methodically , bend them, twist them, if they are split you will see cracks or they will tear. Overall i think it costs about £50 to change them all, its worth doing as these cars are over 15 years old now and rubber just perishes.

 

[Gilly1]

Thanks will do. cleaned mass air sensor and changed 2 small rubber tubes will see how it goes
I am having a go at maintaining car myself as found it costing a lot at garage every time it cost 40 pounds
just to plug in to read code so have brought cheep code reader (cost less than one visit )
also I will know what has been done .Even have a Bentley BMW manual but is a bit hard to follow some times
Thanks again

 

[billysally208]

Also check your fuel filler cap - I replaced mine a few weeks ago with one that was not as tight fit as the old one - I started to get the same code - replaced the old cap and cleared the code and to date it hasn't returned. I also checked all my hoses and like you replaced some of the smaller ones using silicon tubing I bought off Ebay

 

[Tellboy]

You may alsdo finds that if you are getting a P0170 codse this can be triggered by the O2 sensors reaching near the end of their life which is generally around
90 to 100k

 

[colb]

You will save yourself dosh by reading your codes as you have found out by getting a code reader. Interpreting codes is not always straight forward as a sensor creating the code fault is sometimes down to something else in the chain from intake through to exhaust. it's just a matter of lateral thinking to get to the cause. A bad maf will not necessarily set a code directing you to it as the cause, it's either dirty or gone bad or there is an air leak in the system downstream of the maf, perished split rubbers are the Z's worst enemy. It's worth investing in a better diagnostic set up using a Elm327 interface and an App for phone or iPad such as Dash command with this you can watch live data with the engine running and monitor what sensors like the exhaust lambda sensors working and check they are cycling correctly. A lot of people use the BMW Inpa software on a laptop, more involved but can do far more being make and model specific. Do a search for diagnostics on here there are good posts to explain how to etc.

 

[Tellboy]

The reason I mentioned the O2 sensors is when I obtained the car there were several faults and the engine was lacking in maintenance. I have replaced all the hoses , MAF , cam sensor
Water pump, drive belt . new oil filter housing gasket and oil relief valve O rings. The car has been running great then today I had a check engine light come on, when I did a scan it specifically came up with trim fault ,which according to Bently Manual is down to a faulty O2 sensor, and as the car has done just over 96K I suspect that this may well be the cause. I am relacing both the Pre and post sensors , so will let you know what happens.

 

[Zeti]

@Tellboy mine (O2 sensor) gave up at exactly 145tkm. Fuel consumption increased with 50% and I could notice black smoke deposit on the tail of the exhaust. But the code was very precise: "O2 sensor".