CEL from Catless Downpipe

SupraCal

Active Member
First Name
Calvin
Joined
Oct 12, 2020
Messages
30
Reaction score
7
Location
world
Car(s)
Supra MK5
Dear friends,
I am about to embark on making my exhaust sound better with a catless downpipe with a 'L' extension for the O2 sensor.
I read that this may be successful in preventing a CEL.

Can I confirm that even if a CEL occurs, the car will still run fine with no ill effects? also, what can I use to reset/ switch off the CEL whenever it pops up, without having to go down the tuning route with BM3, ECUtek? I plan only to tune after I have done the rest of the mods later.

thanks in advance!





Advertisement

 

Rocksandblues

Well-Known Member
Joined
Sep 21, 2020
Messages
418
Reaction score
327
Location
Virginia
Car(s)
2021 Supra, e46 M3, diesel BMW e90, f250
I have a catless with the elbow extension.

cel came on pretty quickly still. I do not believe there is a solution without a custom tune from ecutek or similar.
 
OP
SupraCal

SupraCal

Active Member
First Name
Calvin
Joined
Oct 12, 2020
Messages
30
Reaction score
7
Location
world
Car(s)
Supra MK5
  • Thread starter
  • Thread Starter
  • #3
Thanks mate.

Will the car run properly without a tune? assuming I can live with the CEL? will it be too lean? hopefully a tuning guru can shed some light on this?
 

Rocksandblues

Well-Known Member
Joined
Sep 21, 2020
Messages
418
Reaction score
327
Location
Virginia
Car(s)
2021 Supra, e46 M3, diesel BMW e90, f250
It will run fine
The tune kills the cel light and maxes out power tweaks and increases.
 

[email protected]

Well-Known Member
Gold Sponsor
Joined
Feb 9, 2020
Messages
201
Reaction score
205
Location
Scottsdale AZ
Car(s)
2020 GR Supra
Usually the tune runs "okay" but at higher speeds I have seen a drivetrain warning thrown for the tune being a bit too far out of spec. I drove for a solid week on a stock tune with a downpipe at one point because I forgot to flash my file due to being so busy.
 

Extreme Power House

Well-Known Member
Gold Sponsor
First Name
Mike
Joined
Nov 7, 2019
Messages
519
Reaction score
238
Location
Las Vegas
Website
x-ph.com
Car(s)
18 BMW M4, 13 Mustang GT
The car runs the same with CEL; it's just a warning light. AFR is the same with catless as your ECU adjusts fueling.
From my experience, O2 spacers are unreliable. Your best bet is to pair the downpipe with bootmod3 for no CEL and a lot more power. :D
 

kona61

Well-Known Member
First Name
Josh
Joined
Mar 25, 2018
Messages
1,007
Reaction score
1,373
Location
San Bernardino-ish, CA
Car(s)
5G 4Runner, MK7 Golf, AZW LE Supra
Vehicle Showcase
1
Just posting my experience, but I installed a 90° spacer off Amazon with a SSR catless DP. I have driven the car about 70 miles so far and have been stepping on it pretty hard. Still don’t have a CEL.
 

Attachments

[email protected]

Well-Known Member
Gold Sponsor
Joined
Feb 9, 2020
Messages
201
Reaction score
205
Location
Scottsdale AZ
Car(s)
2020 GR Supra
Just posting my experience, but I installed a 90° spacer off Amazon with a SSR catless DP. I have driven the car about 70 miles so far and have been stepping on it pretty hard. Still don’t have a CEL.
It took me an entire week to get a check engine light on mine with no spacer... I havent heard of these working at all on this platform to be honest.
 

kona61

Well-Known Member
First Name
Josh
Joined
Mar 25, 2018
Messages
1,007
Reaction score
1,373
Location
San Bernardino-ish, CA
Car(s)
5G 4Runner, MK7 Golf, AZW LE Supra
Vehicle Showcase
1
It took me an entire week to get a check engine light on mine with no spacer... I havent heard of these working at all on this platform to be honest.
Yup, it turned on... P0136 and P013E. I can’t say I’m surprised but was worth the 20$. I’ll just live with the CEL for the time being.
 
OP
SupraCal

SupraCal

Active Member
First Name
Calvin
Joined
Oct 12, 2020
Messages
30
Reaction score
7
Location
world
Car(s)
Supra MK5
  • Thread starter
  • Thread Starter
  • #11
you can turn these codes/CEL off with the OBD2 reader right? and repeat it when necessary.
 

Rocksandblues

Well-Known Member
Joined
Sep 21, 2020
Messages
418
Reaction score
327
Location
Virginia
Car(s)
2021 Supra, e46 M3, diesel BMW e90, f250
You can but I am not sure how long it takes to get a emissions readiness.
You may not be able to clear and pass emissions
 
OP
SupraCal

SupraCal

Active Member
First Name
Calvin
Joined
Oct 12, 2020
Messages
30
Reaction score
7
Location
world
Car(s)
Supra MK5
  • Thread starter
  • Thread Starter
  • #14
Getting the P0141 (sensor heater), P2271 (O2 sensor 2 stuck rich) , P2096(post cat fuel trim too lean) codes.
I have been clearing them on a weekly basis. Any effect on the air fuel ratio/ health of the engine?

local tuner tells me that the second O2 sensor does play a part in the AFR. so blindly clearing it will damage the engine.
 

SupraMKV2.0

Well-Known Member
First Name
Michael
Joined
Jan 5, 2021
Messages
183
Reaction score
173
Location
Wisconsin
Car(s)
2018 Stage III Audi S6, 2019 Audi S4, 2021 Supra
Just a heads up
Getting the P0141 (sensor heater), P2271 (O2 sensor 2 stuck rich) , P2096(post cat fuel trim too lean) codes.
I have been clearing them on a weekly basis. Any effect on the air fuel ratio/ health of the engine?

local tuner tells me that the second O2 sensor does play a part in the AFR. so blindly clearing it will damage the engine.
Your secondary O2 sensor is monitoring the Efficiency of the catalytic converter. With the cat obviously removed, the sensor has no idea what’s going on, so it’s setting a variety of codes.

For the most part, these codes may affect your gas mileage only, but the car remains drivable. I have heard that manufacturers are starting to utilize the rear O2 a little bit more but I’m not sure exactly in which manner.

On a sidenote; I’ve been running a Function Werk Catless downpipe for a few weeks now with NO CEL. This downpipe has an integral defouler that surprisingly works as advertised. I’ve put maybe 450 miles on the car with this DP with all types of driving styles (ie; hard acceleration, constant high cruising loads, slow city driving, etc.) and still no CEL.

I’ve also completed at least 75 key cycles also with no CEL...I’m actually pretty impressed that it works as advertised. As many have stated, often the defouler extension typically do not work, except this defouler is inside the pipe and not considered an extension.
 

Advertisement





 


Advertisement
Top