INSTALLING CATLSS DP & ECU TUNE FIRST TIME HELP
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Newbie
Joined: May 2023
Posts: 7
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Mercedes-Benz C63s Coupe 2021
INSTALLING CATLSS DP & ECU TUNE FIRST TIME HELP
Hello everyone,
I will be installing catless downpipes on my 2021 C63 S Coupe.
This will be my first time getting a vehicle of my own modified. I was hoping if anyone share their own experiences of getting CATLESS DP & ECU TUNE done, what they wish they did, what would've diffeently.
Also, what do should I mention to the tuner? Anything specific I should mention them, or questions to ask?
I'd appreciate all the help, thank you.
I will be installing catless downpipes on my 2021 C63 S Coupe.
This will be my first time getting a vehicle of my own modified. I was hoping if anyone share their own experiences of getting CATLESS DP & ECU TUNE done, what they wish they did, what would've diffeently.
Also, what do should I mention to the tuner? Anything specific I should mention them, or questions to ask?
I'd appreciate all the help, thank you.
Newbie
Joined: Oct 2023
Posts: 9
Likes: 1
W205 C63S
Assuming you are aware that you will most likely fail inspection given you are in an area where they still do inspections, namely emissions? As long as you are aware that's the case and don't care/need to worry about it, then I would get dps installed ASAP. Car sounds so much better with a different set of pipes in 
Member
Joined: Jan 2024
Posts: 201
Likes: 60
From: Colorado
2018 C63S AMG Coupe, 2019 Jaguar F-Pace SVR
Unless you live in an area that doesn't have emissions standards, with totally catless downpipes (aka "straight pipes") you will fail emissions because either:
For the tune you will want a tuner that can extract and save your stock file for the future, not just somebody that change the programming of the ECM. If you ever need to return the car to stock you will want to have the original file (future resale, for example).
Another item for your consideration is whether you want to keep your original downpipes in tact (also recommended for future resale). The only way to remove the OEM downpipes without cutting the pipes is to remove the transmission.
- Your emissions center will see that your tuner turned off the rear O2 Sensors or commanded the CEL off... or
- It will just fail they actual dynamometer sniff test.
- It will fail a visual inspection (if your area does one).
For the tune you will want a tuner that can extract and save your stock file for the future, not just somebody that change the programming of the ECM. If you ever need to return the car to stock you will want to have the original file (future resale, for example).
Another item for your consideration is whether you want to keep your original downpipes in tact (also recommended for future resale). The only way to remove the OEM downpipes without cutting the pipes is to remove the transmission.
