Downpipes

Multaq

Senior Member
First Name
Nick
Joined
Dec 16, 2017
Messages
1,381
Reaction score
548
Location
New York
Car(s)
2018 Civic LX 6SPD
Vehicle Showcase
1
Country flag
Which catted downpipe are people running that also keeps the CEL off during driving. Ive seen a few people say the catted PRL downpipe makes a CEL appear. Disabling the Sensor in Ktuner isnt an option due to state inspections.



Advertisement


 

amirza786

Senior Member
First Name
A
Joined
Oct 4, 2018
Messages
3,636
Reaction score
3,509
Location
Northern California
Car(s)
2006 Camry SE V6, 2013 Toyota Sienna LE, 2010 Lexus IS 350 Sport, 2018 Honda Civic Si (SOLD)
Country flag
Which catted downpipe are people running that also keeps the CEL off during driving. Ive seen a few people say the catted PRL downpipe makes a CEL appear. Disabling the Sensor in Ktuner isnt an option due to state inspections.
I believe you would have to get a tune after installing the DP, as now you have a higher flow, thus the CEL
 

MaTtKs

Senior Member
Joined
Nov 9, 2019
Messages
184
Reaction score
433
Location
Los Angeles
Car(s)
2020 Civic Si Coupe
Vehicle Showcase
1
Country flag
Just ordered a PRL catted DP myself after some research. CEL seems likely but not certain with the PRL. I did see that most people running the AFE DP reported no CEL after a fair amount of use. Also saw many people running the RV6 DP with no CEL.
 

koriw1.5

Senior Member
Joined
Jan 8, 2017
Messages
290
Reaction score
175
Location
Texas
Car(s)
2020 Honda Civic SI Coupe
Country flag
I've seen something about adjusting the O2 sensor so that it isn't so deep inside the downpipe keeps the CEL off. Something about O2 sensor spacer. I can't remember where I saw the post though....
 

koriw1.5

Senior Member
Joined
Jan 8, 2017
Messages
290
Reaction score
175
Location
Texas
Car(s)
2020 Honda Civic SI Coupe
Country flag
I am riding with an AFE Takeda cated DP and I've never
had any problem.
In addition, it makes a nice sound.
Is the AFE 3" all the way through or does it taper down to 2.5" at the end? Can't really tell from there website.
 

casprog

Member
Joined
Jan 2, 2019
Messages
40
Reaction score
37
Location
Socal
Car(s)
2018 Si Coupe
Country flag
Curious but what sort of state inspection are you referring to?

Regarding vehicle smog tests, I heard even catted aftermarket downpipes may not pass, so I just went cat-less PRL. Got Ktuner and disabled the sensor. When it comes time to smog my car I'll just revert the DP to stock.
 
OP
Multaq

Multaq

Senior Member
First Name
Nick
Joined
Dec 16, 2017
Messages
1,381
Reaction score
548
Location
New York
Car(s)
2018 Civic LX 6SPD
Vehicle Showcase
1
Country flag
  • Thread starter
  • Thread Starter
  • #9
Curious but what sort of state inspection are you referring to?

Regarding vehicle smog tests, I heard even catted aftermarket downpipes may not pass, so I just went cat-less PRL. Got Ktuner and disabled the sensor. When it comes time to smog my car I'll just revert the DP to stock.

In New York they just do an OBD 2 test to check your monitors. Youre allowed one monitor to be "Not ready" and still pass. But only one. I am not sure if you can pass when you disable the O2 sensor inside of Ktuner or Hondata. So I would like to find a downpipe that is catted and hope the CEL stays off.
 

ne0guri

Senior Member
Joined
May 22, 2017
Messages
798
Reaction score
794
Location
Mars
Car(s)
2017 White Orchid Pearl Civic Si Sedan
Country flag
I have 27Won catted Downpipe and haven’t had a cel light come on ever, unless KTuner automatically clears it which I’ve been told it doesn’t.
 

MaTtKs

Senior Member
Joined
Nov 9, 2019
Messages
184
Reaction score
433
Location
Los Angeles
Car(s)
2020 Civic Si Coupe
Vehicle Showcase
1
Country flag
Just ordered a PRL catted DP myself after some research. CEL seems likely but not certain with the PRL. I did see that most people running the AFE DP reported no CEL after a fair amount of use. Also saw many people running the RV6 DP with no CEL.
Just to follow up, I’m two weeks into the catted PRL DP being on with no CEL.
 

waterudoing

Senior Member
Joined
Aug 31, 2018
Messages
78
Reaction score
52
Location
Toronto
Car(s)
2018 Honda Civic SI HFP, 3V Mustang, G37xS
Country flag
In New York they just do an OBD 2 test to check your monitors. Youre allowed one monitor to be "Not ready" and still pass. But only one. I am not sure if you can pass when you disable the O2 sensor inside of Ktuner or Hondata. So I would like to find a downpipe that is catted and hope the CEL stays off.
Disabling the O2 sensor will give you a readiness failure during the test. Just get some O2 spacers, and you should pass. I originally failed the test in my 200 cell catted Mustang because my tuner disabled the rear O2. I installed some O2 spacers, and passed with flying colours. I'm sure the tech could smell the gas though lol.
 
OP
Multaq

Multaq

Senior Member
First Name
Nick
Joined
Dec 16, 2017
Messages
1,381
Reaction score
548
Location
New York
Car(s)
2018 Civic LX 6SPD
Vehicle Showcase
1
Country flag
  • Thread starter
  • Thread Starter
  • #13
Disabling the O2 sensor will give you a readiness failure during the test. Just get some O2 spacers, and you should pass. I originally failed the test in my 200 cell catted Mustang because my tuner disabled the rear O2. I installed some O2 spacers, and passed with flying colours. I'm sure the tech could smell the gas though lol.

I found out in my state you are able to have 1 monitor "Not Ready" and still pass inspection. So I am able to get it and just disable the seconday o2
 

CanadiaegeanBlue

Senior Member
First Name
Humza
Joined
Jul 1, 2017
Messages
833
Reaction score
1,357
Location
Toronto
Car(s)
2017 Honda Civic Si Sedan - Aegean Blue Metallic
Build Thread
Link
Vehicle Showcase
1
Country flag
27won Catted DP, no issues :)

Tuned on Hondata
 

koriw1.5

Senior Member
Joined
Jan 8, 2017
Messages
290
Reaction score
175
Location
Texas
Car(s)
2020 Honda Civic SI Coupe
Country flag
Megan Racing Catless.
+500 miles.
No CEL.
No Tune.
Bone Stock.
 

Advertisement












Advertisement


Top