Catted Downpipe Exhaust Fumes

Post Reply
aaronkb
Posts: 4
Joined: Mon Jan 03, 2022 7:59 am

Catted Downpipe Exhaust Fumes

Post by aaronkb »

Hi all,
I had a prl catted downpipe installed on my 2018 EX-T coupe about a month and a half ago. I was already running ktuner stage 1 at the time and still am.

Ever since it’s been installed, my car drives great but I’m getting awful exhaust fumes that I’d expect of a catless dp, not a catted one. I just brought it back to the shop and they triple-checked there’s no exhaust leak. There could be something wrong with the cat, but they also suggested that it could be a tuning issue with the air to fuel ratio not being quite accurate enough.

I know the ktuner basemaps support the downpipe, but I’m sure there’s a difference between supporting it and being optimized for it. Is it possible that this is the cause of the issue, and if so are there tweaks I could make myself in the software to try to correct it? I’m hoping to avoid having to spend the money on a custom tune right now.

Thanks in advance!
Aaron
KTuner
Site Admin
Posts: 3745
Joined: Mon Jul 22, 2013 8:13 pm

Re: Catted Downpipe Exhaust Fumes

Post by KTuner »

If you have an intake that has the MAF housing size altered from factory sizing that could throw fueling off. You have the ability to monitor your air/fuel target, actual, and fuel trims right in the software to verify it's running as commanded. You also have the ability to get a custom tune for your particular setup if you feel you're beyond the included tunes or have an intake like mentioned above. Beyond that you should probably talk to the manufacturer if you have concerns with their aftermarket parts.
aaronkb
Posts: 4
Joined: Mon Jan 03, 2022 7:59 am

Re: Catted Downpipe Exhaust Fumes

Post by aaronkb »

Holy fast reply, Batman! You guys are on it.

Intake is OEM still. Should I take your comment to mean you don’t think a downpipe would throw the mix off?

If I pursue the dead cat explanation I’ll take it up with PRL, but for now I’m trying to find out if there’s a tuning solution.
KTuner
Site Admin
Posts: 3745
Joined: Mon Jul 22, 2013 8:13 pm

Re: Catted Downpipe Exhaust Fumes

Post by KTuner »

Air is metered through the intake at the MAF sensor and appropriate fueling is calculated based on that. Exhaust modifications will not alter fuel delivery unless the O2 placement is causing bad O2 readings while in closed loop.
Post Reply

Return to “16-21 Civic 1.5T”