SL55/63/65/R230 AMG: Check Engine Light after MBH Headers Install
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Joined: Jan 2015
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From: Nations Capital
SL55, 1100 HP Supra, 400 HP GSXR
Check Engine Light after MBH Headers Install
'03 SL55. ECU has not been flashed. Is there a cure for this problem? Also, will the car pass emissions after the ECU flash?
Thread Starter
Junior Member
Joined: Jan 2015
Posts: 30
Likes: 0
From: Nations Capital
SL55, 1100 HP Supra, 400 HP GSXR
Super Member
Joined: Dec 2011
Posts: 531
Likes: 88
From: EDH, CA.
2012 E63 AMG
I know this is an old post, but can you expand on the reason for the CEL issue? Will MBH longtubes make this a permanent issue so car will not pass emissions as long as the headers are on?
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Joined: Feb 2018
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2005 SL55 Completely Built Motor
I believe there is another way to get rid of CEL without a tune. But I don't know why someone would spend money on MBH and not be tuning the car also. I think a large majority of tunes the tuners already bypass the the rear O2's regardless.
I will tell you the MBH headers make a difference. Easily as important as a tune/pulley upgrade. The car becomes much more responsive throughout the rev range. Never dyno'd back to back but I truly believe they do add a solid 40-50HP if not more with what most end up doing to there exhaust in conjunction with the headers. I currently run MBH through custom x-pipe straight to the stock mufflers. Its loud and mean with no drone. If you want it more civil but still a good jump in sound leave the resonators on. But if your dealing with Cali emissions I'm not really sure what you can do. Local performance shop should be able to help you.
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Super Member
Joined: Dec 2011
Posts: 531
Likes: 88
From: EDH, CA.
2012 E63 AMG
I'm almost certain you will not pass emissions with MBH's on without some other work being done. When they are installed your upper cats are removed which cause the rear O2 Sensors to give you the CEL. Someone maybe able to get creative with your exhaust system and add some performance cats to make it all work and pass emissions. Different states have different standards so you'd need to talk to some local performance shops to see what can be done. Maybe it ends up being impossible.
I believe there is another way to get rid of CEL without a tune. But I don't know why someone would spend money on MBH and not be tuning the car also. I think a large majority of tunes the tuners already bypass the the rear O2's regardless.
I will tell you the MBH headers make a difference. Easily as important as a tune/pulley upgrade. The car becomes much more responsive throughout the rev range. Never dyno'd back to back but I truly believe they do add a solid 40-50HP if not more with what most end up doing to there exhaust in conjunction with the headers. I currently run MBH through custom x-pipe straight to the stock mufflers. Its loud and mean with no drone. If you want it more civil but still a good jump in sound leave the resonators on. But if your dealing with Cali emissions I'm not really sure what you can do. Local performance shop should be able to help you.
I believe there is another way to get rid of CEL without a tune. But I don't know why someone would spend money on MBH and not be tuning the car also. I think a large majority of tunes the tuners already bypass the the rear O2's regardless.
I will tell you the MBH headers make a difference. Easily as important as a tune/pulley upgrade. The car becomes much more responsive throughout the rev range. Never dyno'd back to back but I truly believe they do add a solid 40-50HP if not more with what most end up doing to there exhaust in conjunction with the headers. I currently run MBH through custom x-pipe straight to the stock mufflers. Its loud and mean with no drone. If you want it more civil but still a good jump in sound leave the resonators on. But if your dealing with Cali emissions I'm not really sure what you can do. Local performance shop should be able to help you.
Member
Joined: Mar 2016
Posts: 80
Likes: 12
1992 400E, 1997 SL500, 2007 SL55 AMG, 2016 E400
Nor Cal,
Are your headers CARB compliant? If so, please let me know where you got them. I live in CA also and have been trying without success to find CARB approved headers because my smog guy told me that the car wouldn't pass with non-CARB headers.
Thanks,
Are your headers CARB compliant? If so, please let me know where you got them. I live in CA also and have been trying without success to find CARB approved headers because my smog guy told me that the car wouldn't pass with non-CARB headers.
Thanks,
Super Member
Joined: Dec 2011
Posts: 531
Likes: 88
From: EDH, CA.
2012 E63 AMG
I have a California address where smog is not required. Lucky me, if I decide to go that route. The exhaust manifolds are hard to see in the SL and most smog facilities wouldn't even notice. Now the sound might raise their curiosity if a gutted system was in place.
