gsholz

2007 E63 with 44kmiles. I removed the intake carbon filters and replaced the dirty air filters with factory Mann filters. Everthing was perfect for about 10 days but now I'm getting a check engine light. I dropped it off at the dealer (still have 3 days of warranty left) and they replaced a vacuum check valve. The CEL came back after 2 days. The dealer did not notice/mention anything about the missing carbon filters.

Are the missing carbon filters causing the CEL? Are any of you able to run without the carbon intake filters without throwing a CEL? Note I did go with the factory air filters not K&Ns. Do I need to put the carbon filters back?

W109 W211 6.2L

I am rocking no Carbon Filters and K&N on my E63 and no problems. Altho i did do the moddification is stages. I removed the carbon filters for 500 miles leaving the stock Mann air filters. I then bought K&N filters and I let them sit in front of a fan with a towel under them to absorb the oil for 5 days and installed them.

To this point no CEL car has around 17k miles.

Peter_02AMG

I been running without carbon filters for almost 2yr and no CEL.

220S

iirc, some people have had a CEL w/carbon out and the OEM filters (no K&N.) Why not pop the carbons back in and drive around for a week or so and see what happens. If you get another CEL then you can eliminate the filters.

DAGREEKNYC

WOW this is a uncommon thread

NCE500

I doubt that removing the carbon filters and using OEM airfilters would throw a code....something else is probably wrong. Hard to say for sure without knowing the actual code, but you may well have an intake gasket vacuum leak which will throw a code. I had a similar CEL situation last year, popped the carbon filters back in, but still had CEL. Took it to the dealer, they diagnosed a lean cylinder bank, replaced the intake gaskets, and the car has run perfectly since. I re-removed the carbon filters about a week after getting the car back, no issues at all. They said the intake gasket leak is a fairly common problem.

Hope they will still cover you under warranty as you brought it in before expiration.

bmontalban

^^^ same for me. Probably managed to damage the gaskets during filter replacement/charcoal removal and dicking with the airboxes. day and half later at the dealer, runs like a champ, no CEL.

gsholz

The first time I brought it in the codes were 0817/0821 [secondary valve jammed open for bank 1 & 2] and 0745 [self adaptation for enriching mixture at idle above permissible limit] and 2091 [mixture right bank too lean when idling]. They replaced a vacuum valve and values tested ok afterward but CEL came back on after 2 days.

I dropped it off again and now they think it is an intake gasket leak just like you mentioned. Not sure what gasket they are referring to- I'll find out

Thanks for all the responses!

blair_mbz

Removing carbon filters will 100% NOT throw a CEL. It does sound like you have an intake or some kind of leak somewhere. Keep in mind cars in Europe don't have charcoal filters so no CEL issues there.

I always like to go back to a know condition. Which meas out the charcoal filters back on, reset the CEL and see what happens. I'm certain CEL will come back on.

Good luck!

gsholz

I should get my car back today. They replaced the intake manifold gasket - quite a bit of work. One of the emission related hoses cracked when they removed it, so they had to order a new one.

Anyway, thinking about the codes/descriptions, since the codes indicate being lean at idle it can't be related to the air filter/carbon filter. The throttle plate is almost fully closed at idle with little air flow but high vacuum in the manifold. Any gasket leak would show up at idle. Makes sense.

I'm surprised how well it idled though even with the leak.

gsholz

Update: I got the car back the 2nd time. The code was 0745 again [self adaptation for mixture enrichment at idle is above permissible limit]. Essentially too lean at idle.

They replaced the "resonance intake manifold gasket to the cylinder head" per document 09.20-P-045901 for leaking intake manifold gaskets.

Intake manifold leaks seem relatively common on these cars given that there is a maintenance doc on it.

The CEL was not related to the carbon filter removal.

FromM3toAMG

why is everyone running K&N filters? something wrong with BMC filters?