Carly Error Code - O2 sensor

[Madtoady]

Would anyone mind confirming what these error codes could mean and the possible fix?

I managed to get my car through its MOT and went for a spirited drive at the weekend and the engine warning light popped up. It was a very warm day. It's the first time I plugged the car into the app so I'm not 100% sure which code made the light come on. I reset the codes to see if anything came up again. I've used the car a couple of times since and had no problems until today when the warning light came on on my way to work this morning.

I've not had chance yet to recheck which code has come back but would be nice to prepare myself for the possible fix. Thanks.

 

[Madtoady]

So it's the Lambda regulator probe for Bank 2 which needs to be replaced. The regulator probe I believe is the one before the cat? And Bank 2 is the yellow arrow in this image?

 

[Madtoady]

11781437586

That seems to be the part number for the correct sensor although RealOEM states its for automatic transmission vehicles

 

[Madtoady]

So... I bought this: Lambda Sensor Pre Cat 00 to 06 Oxygen Bosch 11781437586.

The part came last week and I attempted to replace the part this weekend. I Totook the cam covers off the engine and that's where I became stuck. I could not find the sensor. It definitely wasn't where I was expecting it to be.

This is the guide I used and I can only assume that this was for the Pre face-lift models:

https://www.pelicanparts.com/BMW/te...ment/08-EXHAUST-Oxygen_Sensor_Replacement.htm

Anyone know where this sensor is that I need to replace or if I even bought the correct part. Thanks

 

[Jack Ratt]

The photo in the Pelican guide is a facelift twin vanos engine. Have a look at the comments at the end of the feature from Frank C and the reply from Pelican.
My car is pre facelift so not the same as yours so can't offer personal knowledge

 

[NZ00Z3]

The first engine code: 27 BLS-BTS plausibility- is telling you that the brake switch is stuffed.

The Lamba code is likely telling you that you have a vacuum leak in the rubber boots/ hoses.

 

[Madtoady]

The first engine code: 27 BLS-BTS plausibility- is telling you that the brake switch is stuffed.

The Lamba code is likely telling you that you have a vacuum leak in the rubber boots/ hoses.

Hmmm, so I'm wasting my time replacing the sensor?

 

[NZ00Z3]

Hmmm, so I'm wasting my time replacing the sensor?

Generally yes, The code has the word "deviation" in it, saying that the reading from the probe is out of acceptable range. It could be the probe, but usually its a sign of a vacuum leak. Other symptoms are your engine idling a little rough when cold and your fuel economy will be down.

Common causes of vacuum leaks are:
- A break in the bend of the small rubber hose going to the idle control valve. It is located as a branch off the main rubber tube going to the throttle body.

- Damaged vacuum hoses, usually 3.5 mm diameter

- Split vacuum port caps on the end of the inlet manifold

Hope this helps

 

[NZ00Z3]

Check your fuel trims with your scanner to confirm the vacuum leak problem. The short term ones will be positive and the long term ones will be about 8. When above 8 they set the check engine light.

 

[Madtoady]

Hmmm, I've managed to recheck the codes and now both bank 1 and 2 are popping up. Does this help diagnose the problem? I've got a car show on Sunday so would like it fixed

 

[Madtoady]

Got it plugged in at a garage.

Cleaned the mass air flow meter and reset the codes. Hopefully that might do it.

 

[NZ00Z3]

The system too lean = vacuum leak letting in air after the MAF leaning out the mixture. The Lamba probe is measuring the lean condition and telling he DME to put more fuel in. The condition has got so bad that it is now bringing up the check engine light.

Do not pass go, return to post #8 and look for the leak.

 

[Madtoady]

The system too lean = vacuum leak letting in air after the MAF leaning out the mixture. The Lamba probe is measuring the lean condition and telling he DME to put more fuel in. The condition has got so bad that it is now bringing up the check engine light.

Do not pass go, return to post #8 and look for the leak.

Give that man a medal!

The induction tube elbow has a split that I can put my finger into!

 

[NZ00Z3]

Well done, great result.

 

[Madtoady]

I'm pretty sure this was the problem!