im3cpo

I removed the charcoal filters and replaced the air filters with non-oiled high flow filters from Weistec. I ended up getting a CEL after maybe 30 miles or so of driving. CEL code was Bank1 running too lean. I put the charcoal filters back in but left the Weistec air filters in place and cleared the code. Everything seems to be back to normal and have not gotten a CEL (yet). Just curious if this is considered normal or if I just happen to have a really picky firmware on my car....

Sincity

I've heard this happen before to JonsC63 (I think that is his username). Did you correctly seated the box top half with the lower half and tighten all the screws? I think that is what some people have done. I've taken mine off without issues for the past 10k miles.

Mort

Seems to me this was a reported issue on a lot of '09s but not so much on the newer cars. If your install is good and no leaks downstream of the MAF then it might be that your ECU will adjust the fueling after a few days. A few people have reported that the ECU did adapt after driving for a while.

tfthach13

The 2009s tends to be a bit sensitive for some odd reason. For some people, there's no problem, but most will experience CELs. I believe that's it's just the computer not liking the increase in air flow. AND it doesn't adapt either; I've tried.

So like you, I put the charcoals back in with the dry filters and just left it at that. The only real thing you're missing out on is a slightly louder engine note. Performance gains is negligible.

CoolBDPhenom03

It could also be the fitment of the filters. I think the '09s are very finicky unless you put the filters in exactly right.

edwardsflight33

Was this on an '09 or your 507?

im3cpo

This was on my 507. I triple checked everything and did my best to ensure there were no leaks. Everything appeared to be installed correctly and the air boxes were very secure.

Shelby GT500's tend to have a similar issue but its been traced down to turbulence around the MAF sensor with some setups. The plastic that actually holds the charcoal filter in place does have several braces that would cause the same types of turbulence the GT500's experience. Not sure if that is part of it or not....

Is there a way to force the computer to reset after taking out the filters to relearn and apply more fuel? Perhaps my car just didn't want to adapt?

DavidZhu

I got a 2013 c63 but i used K&N filters instead and never got a CEL. its been at least 1k miles since i removed the charcoal filters

CoolBDPhenom03

You can disconnect the battery to reset the CEL. Or just keep driving it to see if your ECU adapts. Some folks said theirs reset. I haven't had issues on mine and I've had K&Ns for over 30k miles with a charcoal delete. A tune or reflash could also help.

im3cpo

Thanks for the info... What's strange is that I did try disconnecting the battery overnight (both terminals even). When I hooked everything back up the next day, CEL was still there and *ALL* my setting for the car were still intact too! I ended up having to use a scan tool to delete the codes and go from there. Not ever heard of a battery disconnect not working before, but.......

I also figured a new tune would be a good route for a solution, but not quite sure I want to go to that point yet since the car is so new. I will most definitely go that route once it gets some miles on it though!

CoolBDPhenom03

Try giving it a few days to see if the CEL goes away. Otherwise make sure the filter fit is right. That's all I can think of.

im3cpo

Thanks for the help! I will give it a shot and see what happens.