Code PO170 - Powertrain Fuel Trim (Bank 1)

[Ian Wilcox]

I have had fault code PO170 - Powertrain Fuel Trim (Bank 1) on a 2001 Z3 1.9 coming up for quite a while. So far I have changed all the vacuum pipes on the top of the engine, changed the post and pre cat exhaust sensors and had no luck so far. Has anyone else come across this fault and managed to solve it.

Grateful for any advice and help

Thanks in advance

 

[NZ00Z3]

The easiest way to find the vacuum leak is to smoke test the engine. Read: https://www.e46fanatics.com/threads/how-to-smoke-test.1261077/#post-18615547

 

[AntStark]

Check this pipe after the MAF. They are usual suspect for vacuum leaks, splits are hard to see in the concertinaed bit.

Also ....... https://zroadster.org/threads/another-day-another-fault-code.50717/

 

[Ian Wilcox]

Check this pipe after the MAF. They are usual suspect for vacuum leaks, splits are hard to see in the concertinaed bit.


View attachment 276841
Also ....... https://zroadster.org/threads/another-day-another-fault-code.50717/

Quick question on what I think is a non return valve on the vacuum hose (black/white) on this pic you sent it seems to be the opposite way round to mine and the other pic I found (see attached) , which is the correct way?

 

[AntStark]

Black bit at the top I think … like yours is