Help with CEL/emissions

[Sleeper519]

I've had a CEL for couple of weeks, saying "increased emissions". Stock exhaust. I went to local reputable BMW shop yesterday for a new battery and registration so I had him check and clear codes (was pissed that he charged me $89 for that). He said it could be from the electrical/weak battery and may not recur. Well it came back today. I checked the printout and the codes are:
2739 - air mass sensor sec. Air electrical diagnosis.
27c5 - air mass sec air plausibility.

Not sure if I should go to stealership (hate!) or back to local shop but i want to have some idea of what we're talking about so I'm not going in blind.

Can anyone interpret these fault codes? I'm out of warranty and don't want to be taken for a ride so to speak (especially at dealer).

Thanks.

[RBB]

Your secondary air pump has failed and will need to be replaced. I have no idea what the cost is on that. You might want to check realoem to at least give you an idea on the part cost.

[radiognome]

Originally Posted by Sleeper519

I've had a CEL for couple of weeks, saying "increased emissions". Stock exhaust. I went to local reputable BMW shop yesterday for a new battery and registration so I had him check and clear codes (was pissed that he charged me $89 for that). He said it could be from the electrical/weak battery and may not recur. Well it came back today. I checked the printout and the codes are:
2739 - air mass sensor sec. Air electrical diagnosis.
27c5 - air mass sec air plausibility.

Not sure if I should go to stealership (hate!) or back to local shop but i want to have some idea of what we're talking about so I'm not going in blind.

Can anyone interpret these fault codes? I'm out of warranty and don't want to be taken for a ride so to speak (especially at dealer).

Thanks.

I had the same message appearing and disappearing for a while until it started saying that one of the sensors failed. At stealership they charged me $800 to replace it (out of warranty). Later I found out that it could cost me around $150 to buy a new sensor and that it was not so difficult to replace it myself.

[Sleeper519]

Originally Posted by RBB

Your secondary air pump has failed and will need to be replaced. I have no idea what the cost is on that. You might want to check realoem to at least give you an idea on the part cost.

Thanks... What does a secondary air pump do??

[BPMSport]

Originally Posted by Sleeper519

Thanks... What does a secondary air pump do??

Warms up the cats for emissions purposes by pumping air into the secondary air passageways.

If you get a tune this whole thing can be removed and will probably cost you around the same.

[RBB]

Originally Posted by Mike Benvo

Warms up the cats for emissions purposes by pumping air into the secondary air passageways.

If you get a tune this whole thing can be removed and will probably cost you around the same.

That's good advice....it'll be money well spent. Just get a tune with cold start deleted and problem solved. The secondary air pump serves no other purpose.

[Sleeper519]

Thanks, Mike, good info. I've resisted a tune before because I'm "too stock" to benefit much. No?

[BPMSport]

Originally Posted by Sleeper519

Thanks, Mike, good info. I've resisted a tune before because I'm "too stock" to benefit much. No?

Take a look at the bottom of this link. No such thing as "too stock" to benefit

Http://www.bpmsport.com/BPMTune.pdf

I'd say that roughly half of the cars we tune are stock.

[Sleeper519]

Stupid question: I've got to do emission testing in May--I won't pass it with this CEL still throwing, will I??...

[BPMSport]

Originally Posted by Sleeper519

Stupid question: I've got to do emission testing in May--I won't pass it with this CEL still throwing, will I??...

Impossible to pass with a CEL.

Also impossible to pass if you clear the CEL and take it straight to the smog place.