Im the big dumb

Surfercano2

Member
First Name
Christian
Joined
Apr 12, 2021
Threads
3
Messages
13
Reaction score
4
Location
Texas
Vehicle(s)
2019 Honda Civic Si TYP
Country flag
Recently been having some really strange readings on my 10th gen si with regards to fuel trims. Thought I had a vacuum leak or a messed up ewg or egr valve or whatever could cause lean fuel trims. Turns out I have too much airflow because the previous owner went catless and my stock tune couldn't compensate. So now I have a good tune but I need to add a cat so I am compliant. Looking at 27w0n downpipe but I am curious. Do I need a front pipe and a downpipe or just the catted downpipe?
Sponsored

 

gtman

Senior Member
First Name
Mitch
Joined
Oct 27, 2015
Threads
328
Messages
16,661
Reaction score
24,352
Location
USA
Website
www.civicx.com
Vehicle(s)
2017 Cosmic Blue EX-L Sedan
Vehicle Showcase
2
Recently been having some really strange readings on my 10th gen si with regards to fuel trims. Thought I had a vacuum leak or a messed up ewg or egr valve or whatever could cause lean fuel trims. Turns out I have too much airflow because the previous owner went catless and my stock tune couldn't compensate. So now I have a good tune but I need to add a cat so I am compliant. Looking at 27w0n downpipe but I am curious. Do I need a front pipe and a downpipe or just the catted downpipe?
What were your fuel trims reading and do you have an aftermarket intake?

If you're tuned, there are also settings within the software so the catless downpipe won't throw codes.
 
Last edited:
OP
OP

Surfercano2

Member
First Name
Christian
Joined
Apr 12, 2021
Threads
3
Messages
13
Reaction score
4
Location
Texas
Vehicle(s)
2019 Honda Civic Si TYP
Country flag
What were your fuel trims reading and do you have an aftermarket intake?

If you're tuned, there are also settings within the software so the catless downpipe won't throw codes.
I do have a injen evo 1500 I believe and my trims were at 14%long term and between 0- and 45% short term. Since I have had the tune my long term has stabilized and my short term is much less erratic. I'm currently running MAP stg 1 map 2 and having very few issues. Now another new question, if I do not have a flex fuel conversion kit, would ktuner still show an ethanol voltage reading?

Honda Civic 10th gen Im the big dumb 16353698546024836748770147363676
Sponsored

 


 


Top