ISR Race Exhaust Catback - Hyundai Genesis Forum
  • 2 Post By GenRacer Support
  • 1 Post By guybo
LinkBack Thread Tools
post #1 of 5 Old 04-01-2016 Thread Starter
Junior Member
Join Date: Apr 2016
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
ISR Race Exhaust Catback

Just last weekend, I had my ISR straight through catback race exhaust installed on my 3.8 Genesis Coupe. I've been driving it around for about 5 days and I'm now experiencing some mpg issues. My average mpg plummeted from 19-18 to around 13. I know... this sounds crazy. Some people are saying that this shouldn't happen at all. The fuel gauge and the miles remaining meter are also completely out of sync. It is usually out of sync slightly, but it's getting way out of hand. The screen indicated that I had 70 miles left while in actuality, my tank had less than 30. Does anyone here have an answer and a solution to this? Is this happening to anybody else with this same mod? I really don't want to remove the exhaust (because it sounds amazing) but I might have to if this issue isn't resolved.

PS. Please be kind and helpful.
npearso1 is offline  
Sponsored Links
post #2 of 5 Old 04-04-2016
Genesis OG
J Long's Avatar
Join Date: Mar 2010
Location: Nashville, TN
Posts: 2,625
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 190 Post(s)

I had the ISR Race on my 3.8 and did not have this issue. They sound unrelated. Try resetting your ECU. But might be a fuel tank issue.

2013 3.8 Track M/T

BC Racing Coilovers
R2C Intake
ARK Downpipes
ARK Test Pipes
Custom CNT V3 w/ X pipe
SFR Custom Tuned
Dolphin Grey Work Varianza/AG M560
19x9.5 +15 235/35 Achilles ATR Sport
19x11 +18 265/30
Xenon Depot 6500K D1S HIDs
6000K Switchbacks
6000K LED Fogs
Full Time DRL's
RGB Halos
Custom Interior LED Kit
6W Reverse LEDs
20% Tint
J Long is offline  
post #3 of 5 Old 04-04-2016
The OG Gencoupe Shop
GenRacer Support's Avatar
Join Date: Feb 2009
Location: Milford, CT
Posts: 4,589
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)

It may have a direct relation of wanting to hear sound and accelerating fast to your MPG.

An exhaust wont affect your MPG like this. Its most likely driving habits have changed a little
J Long and guybo like this.


Free Shipping for orders over $500, limits apply


[ now accepting WHOLESALE accounts ]

GenRacer Support is offline  
post #4 of 5 Old 04-04-2016
Senior Member
Join Date: Nov 2014
Posts: 145
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 40 Post(s)

I get a measured 22 - 24 all day long and I'm pretty damn hard on my car, you must have something else going on. Try different gas, I've had bad gas wreck my mileage before.

'15 3.8 Coupe R spec MT ESG - Ark Grip - R2C Short Ram
Shitchya is offline  
post #5 of 5 Old 04-05-2016
Senior Member
Join Date: Feb 2015
Location: Tampa, fl
Posts: 1,013
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 276 Post(s)

You've had it for 5 days. Just drive and don't worry. If it's thesame way in a month, then start getting concerned.
GenRacer Support likes this.

guybo is offline  
Sponsored Links

Related Threads
Thread Thread Starter Forum Replies Last Post
[FS] ISR (Isis) race exhaust 2.0T Sane1 Engine 3 02-25-2016 07:41 AM
ISR Race exhaust emission problem? Skhan47 2.0T Discussion 2013 and up 21 02-23-2016 01:07 PM
ISR Street Catback vs TurboXS RSD Catback Kev651 General Discussion 1 12-13-2015 09:27 PM
ISIS catback race exhaust or street? Skerrit 2.0T Discussion 2008-2012 39 05-13-2014 09:22 AM
FS/FT Isis Race Catback exhaust RIPFWD Engine 6 12-08-2012 10:59 AM

3.8 , exhaust help , genesis coupe , mpg

Quick Reply

Register Now

In order to be able to post messages on the Hyundai Genesis Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome