Removing both of the rear CAT's
Thread Starter
Member
Joined: Apr 2012
Posts: 107
Likes: 1
From: Ogden, UT
2007 SL550
Removing both of the rear CAT's
I just have a question if anyone has removed the rear CAT's? and have they got any kind of check engine light or any error codes?? I know that the rear CAT's aren't connected to a O2 sensor, but i just want to make sure before going to the muffler shop removing those and then later on getting a check engine light and also most importantly, has it passed an emission test? Please help me. Also i have removed the resonator and put in a magnaflow muffler in the place of the stock muffler. Here is a video of the exhaust note of my car.
Last edited by vishanthram; Apr 25, 2014 at 02:25 AM. Reason: Add more info
Super Member
Joined: Dec 2009
Posts: 748
Likes: 93
From: Dhahran, KSA
2020 E 300 Coupe and 2019 GLS 400
I think you'll find a lot of threads about rear cat delete.
Never mind, the sensor only monitors the front ones. you will NOT get any CEL.
For the emission test, it depends if they use the sniffing test, visual or OBD.
Some people reported passing the sniffing test after 2nd cat delete.
Regarding the visual, it depends on the place you go to and the experience of the bloke ( if he knows Mercedes has 4 cats, you might fail). As for the OBD, you'll pass as long as your 1st set is working and the OBD has all the readings.
Faiz
Never mind, the sensor only monitors the front ones. you will NOT get any CEL.
For the emission test, it depends if they use the sniffing test, visual or OBD.
Some people reported passing the sniffing test after 2nd cat delete.
Regarding the visual, it depends on the place you go to and the experience of the bloke ( if he knows Mercedes has 4 cats, you might fail). As for the OBD, you'll pass as long as your 1st set is working and the OBD has all the readings.
Faiz
Thread Starter
Member
Joined: Apr 2012
Posts: 107
Likes: 1
From: Ogden, UT
2007 SL550
Great info
I think you'll find a lot of threads about rear cat delete.
Never mind, the sensor only monitors the front ones. you will NOT get any CEL.
For the emission test, it depends if they use the sniffing test, visual or OBD.
Some people reported passing the sniffing test after 2nd cat delete.
Regarding the visual, it depends on the place you go to and the experience of the bloke ( if he knows Mercedes has 4 cats, you might fail). As for the OBD, you'll pass as long as your 1st set is working and the OBD has all the readings.
Faiz
Never mind, the sensor only monitors the front ones. you will NOT get any CEL.
For the emission test, it depends if they use the sniffing test, visual or OBD.
Some people reported passing the sniffing test after 2nd cat delete.
Regarding the visual, it depends on the place you go to and the experience of the bloke ( if he knows Mercedes has 4 cats, you might fail). As for the OBD, you'll pass as long as your 1st set is working and the OBD has all the readings.
Faiz
Do you know if these air filters are any good?
http://www.summitracing.com/parts/knn-33-2747/overview/
I have been reading and one of our trusted member, ohlord, said especially not to use K/N air filters and i want to know why. Thanks for the info. Happy
Super Member
Joined: Dec 2009
Posts: 748
Likes: 93
From: Dhahran, KSA
2020 E 300 Coupe and 2019 GLS 400
Okay, im gonna drop the rear CATS and put straight pipes in their place, lets hope that i dont fail emissions and also i hope that you are right about the CEL codes.
Do you know if these air filters are any good?
http://www.summitracing.com/parts/knn-33-2747/overview/
I have been reading and one of our trusted member, ohlord, said especially not to use K/N air filters and i want to know why. Thanks for the info. Happy
Do you know if these air filters are any good?
http://www.summitracing.com/parts/knn-33-2747/overview/
I have been reading and one of our trusted member, ohlord, said especially not to use K/N air filters and i want to know why. Thanks for the info. Happy
Regarding the air filters, K&N requires to be oiled every now and then. And sometimes the oil contaminates the MAF sensor which throws codes and cause performance issues.
Currently I'm using AFE Pro dry S filters.
http://www.summitracing.com/int/part...0084/overview/
You can read my review at:
http://www.summitracing.com/int/part...10084/reviews/
Best of luck.
Thread Starter
Member
Joined: Apr 2012
Posts: 107
Likes: 1
From: Ogden, UT
2007 SL550
Oiling air filters?????
Why not install an x-pipe in place of the cats? I know you already have one inside the muffler. but placing the x-pipe as close to the engine will net you most gains and eliminate drone.
Regarding the air filters, K&N requires to be oiled every now and then. And sometimes the oil contaminates the MAF sensor which throws codes and cause performance issues.
Currently I'm using AFE Pro dry S filters.
http://www.summitracing.com/int/part...0084/overview/
You can read my review at:
http://www.summitracing.com/int/part...10084/reviews/
Best of luck.
Regarding the air filters, K&N requires to be oiled every now and then. And sometimes the oil contaminates the MAF sensor which throws codes and cause performance issues.
Currently I'm using AFE Pro dry S filters.
http://www.summitracing.com/int/part...0084/overview/
You can read my review at:
http://www.summitracing.com/int/part...10084/reviews/
Best of luck.
I read your review and i totally agree with the sound. For the first time my car crackled when up shift. Never has it done that before. I did not know that K/N filters had to be oiled!! Oiling air filters?? WHAT THE HECK, i've never heard of such thing and i am going to buy the AFE air filters then. Im going to return the K/N air filter that i bought, good thing its still sitting in the package.
Super Member
Joined: Dec 2009
Posts: 748
Likes: 93
From: Dhahran, KSA
2020 E 300 Coupe and 2019 GLS 400
Straight pipes are the loudest, but the drone might be unbearable. I think an H is a little bit louder than an X.
H= muscle car sound
X= exotic sound
Thread Starter
Member
Joined: Apr 2012
Posts: 107
Likes: 1
From: Ogden, UT
2007 SL550
Sorry for the no response. I had my school finals. I want the exotic sound not like a mustang sound on a Mercedes. So as per your posting, im gonna go with a the x pipe. Thank you so much for the info.
Trending Topics
Thread Starter
Member
Joined: Apr 2012
Posts: 107
Likes: 1
From: Ogden, UT
2007 SL550
And also i returned the K&N filter and bought the aFe Pro dry filter. I haven't noticed any exhaust sound changes as you mentioned in your review. I noticed the K&N filter was oily when taken out of the box and i asked around couple of other people and they said exactly what you said. That the oil will sometime contaminates the MAF sensor and throws off codes and sometimes CEL.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
Super Member
Joined: Dec 2009
Posts: 748
Likes: 93
From: Dhahran, KSA
2020 E 300 Coupe and 2019 GLS 400
And also i returned the K&N filter and bought the aFe Pro dry filter. I haven't noticed any exhaust sound changes as you mentioned in your review. I noticed the K&N filter was oily when taken out of the box and i asked around couple of other people and they said exactly what you said. That the oil will sometime contaminates the MAF sensor and throws off codes and sometimes CEL.
