Air filter and check engine light

renpar61 · 10-30-2009, 12:15 PM

I replaced the air filter on a 2008 E93 with a K&N filter. After a couple of days the "Service Engine Soon" light came up. The car shows no sign of malfunction. Contacted the dealer and said is probably emission related, made appointment to run diagnostic.
I looked under the hood and realized the tube out of the filter box was a little loose and starting to come off on one side. Which I believe could have triggered the check light. I fixed it and now getting ready to take the car to the dealer.
Should I tell them about this or should I wait for them to run diagnostics and see what they say? I would hate for them to blame it on the K&N air filter itself and charge me to change it back.
Any suggestions?

ENINTY · 10-31-2009, 07:17 AM

If I were you I'd replace the K&N with the OEM filter if you kept it. If there is something wrong with the intake system that caused the CEL then BMW is going to charge you for it. Also it might be a good idea to get the code read before you go to the dealer. Autozone and other stores provide OBDII checks for free. Understand what the code is before you go to the dealer.

If K&N filters are over-oiled when installed they can contaminate the mass airflow sensor. I assume your filter was new, so it's a low probability that that happened, but it is possible. However it really sounds like you had an air leak in the intake behind the MAF, which threw the CEL.

FCP Euro · 11-03-2009, 07:31 PM

^^^

I agree with ENINITY. You do not want to role in there with a K&N filter in there. They will blame it on you and you will have to pay to have it converted back.

renpar61 · 11-04-2009, 03:32 PM

Actually, I didn't have time to change the filter and my assumption was wrong. The SES light was triggered by a faulty valve. They are replacing it under warranty. No mention about the K&N filter (if they even saw it...)
I should pick up the car tomorrow.

FCP Euro · 11-06-2009, 09:01 AM

They probably never saw it. That is a that the SES light came on when it did.

10-30-2009, 12:15 PM	#1
renpar61 Private 6 Rep 51 Posts Drives: BMW 430i coupe Join Date: Sep 2008 Location: MD iTrader: (0)	Air filter and check engine light I replaced the air filter on a 2008 E93 with a K&N filter. After a couple of days the "Service Engine Soon" light came up. The car shows no sign of malfunction. Contacted the dealer and said is probably emission related, made appointment to run diagnostic. I looked under the hood and realized the tube out of the filter box was a little loose and starting to come off on one side. Which I believe could have triggered the check light. I fixed it and now getting ready to take the car to the dealer. Should I tell them about this or should I wait for them to run diagnostics and see what they say? I would hate for them to blame it on the K&N air filter itself and charge me to change it back. Any suggestions?
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10-31-2009, 07:17 AM	#2
ENINTY Banned 172 Rep 3,415 Posts Drives: 2006 325i Sport Join Date: Jun 2006 Location: Virginia iTrader: (0)	If I were you I'd replace the K&N with the OEM filter if you kept it. If there is something wrong with the intake system that caused the CEL then BMW is going to charge you for it. Also it might be a good idea to get the code read before you go to the dealer. Autozone and other stores provide OBDII checks for free. Understand what the code is before you go to the dealer. If K&N filters are over-oiled when installed they can contaminate the mass airflow sensor. I assume your filter was new, so it's a low probability that that happened, but it is possible. However it really sounds like you had an air leak in the intake behind the MAF, which threw the CEL.
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11-03-2009, 07:31 PM	#3
FCP Euro Lieutenant 10 Rep 462 Posts Drives: Volvo 850 T5 Join Date: Aug 2009 Location: Old Saybrook, CT iTrader: (0)	^^^ I agree with ENINITY. You do not want to role in there with a K&N filter in there. They will blame it on you and you will have to pay to have it converted back. __________________ sales@fcpeuro.com FCP Euro - European Car Parts Specialists
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11-04-2009, 03:32 PM	#4
renpar61 Private 6 Rep 51 Posts Drives: BMW 430i coupe Join Date: Sep 2008 Location: MD iTrader: (0)	Actually, I didn't have time to change the filter and my assumption was wrong. The SES light was triggered by a faulty valve. They are replacing it under warranty. No mention about the K&N filter (if they even saw it...) I should pick up the car tomorrow.
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11-06-2009, 09:01 AM	#5
FCP Euro Lieutenant 10 Rep 462 Posts Drives: Volvo 850 T5 Join Date: Aug 2009 Location: Old Saybrook, CT iTrader: (0)	They probably never saw it. That is a that the SES light came on when it did. __________________ sales@fcpeuro.com FCP Euro - European Car Parts Specialists
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