Running Rich

65thKJ · **Posted:** Sat Mar 17, 2007 5:29 pm

I put a Mopar Borla exhaust on my liberty about 1 month ago. The exhaust tips are stainless so I really notice that the bottoms of them get black soot on them. Even if I wash them it reaccumulates after 1 or 2 days. I didn't notice this w/ the stock exhaust because the tip was up higher and not shiny. If I stand behind the Jeep when it is running I do notice that it smells like it is running rich. Do these Liberties run rich from the factory? Or maybe I should get it checked out at the dealership?

Hood297 · **Posted:** Sat Mar 17, 2007 5:37 pm

I have also had the exact same thing happen to mine when traded my stock muffler for a flowmaster and added a tip to it, same exact problem as 65thKJ described above...

Im also curious as to what is causing this...

65thKJ · **Posted:** Mon Mar 19, 2007 9:49 am

Anyone?

tjkoen01 · **Posted:** Tue Mar 20, 2007 7:28 am

I too have noticed what appears to be carbon buildup on my SS exhaust tip. I haven't noticed it smelling like it was running rich, so I didn't think much of it.

Maximum Carnage · **Posted:** Tue Mar 20, 2007 8:07 am

Give them some time; I’m sure someone is out their franticly searching.

tjkj2002 · **Posted:** Tue Mar 20, 2007 8:24 am

65thKJ wrote:

I put a Mopar Borla exhaust on my liberty about 1 month ago. The exhaust tips are stainless so I really notice that the bottoms of them get black soot on them. Even if I wash them it reaccumulates after 1 or 2 days. I didn't notice this w/ the stock exhaust because the tip was up higher and not shiny. If I stand behind the Jeep when it is running I do notice that it smells like it is running rich. Do these Liberties run rich from the factory? Or maybe I should get it checked out at the dealership?

My Borla exhuast is the same way,like you said you didn't notice it before due to the stock pipe being out of the way.When you first start your KJ and till the O2 sensors reach about 600-650 degress you are in "open loop" which means you are on a preset control on fuel delievery and stark control.As soon as the O2 sensors are heated up and start sending the PCM signals then you go into "closed loop" and your PCM adjusts fuel and timing off the O2 sensors.So yes if it is fairly warm out when you first start your KJ it is running rich,nothing you can do about it till the O2 sensors are heated up.Now if it still smells like it's running rich when fully warmed up then your check engine light should turn on telling you one of your O2 sensors is not working.Plus it took a 2 months of running the Borla to get all the preservitive oil burned out of the Borla muffler,that may be what you are smelling.

65thKJ · **Posted:** Tue Mar 20, 2007 11:48 am

tjkj2002 wrote:

Plus it took a 2 months of running the Borla to get all the preservitive oil burned out of the Borla muffler,that may be what you are smelling.

That might be it, because it does seem like it is getting less build up as time goes on. I think I'll just give it another month. Plus I have been doing mostly short trips so maybe it from the multiple warm ups and running in open loop.

Boi1ermaker · **Joined:** Tue Jan 24, 2006 1:44 pm **Posts:** 249

I've had the dual mopar exhaust for about a year now...and i the soot still builds up fairly quickly. Most of my trips are 30+ highway miles, but since its always pretty warm around here sounds like there's not much i can do about it.

2006KJSPORT4x4 · **Posted:** Tue Mar 20, 2007 12:46 pm

My check engine light couldn't read that one of my O2 sensors was bad. I ended up losing my Catalytic convertors. Had them replaced along with all the spark plugs and O2 sensors...tahnk God for warranty work...hopefully won't happen again...

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

The Libby does run pretty rich when we dyno it. I've had my Borla/Mopar dual for over 5 years. It doesn't stop happening. I just pull out the Mother's polish every once in a while and make them nice and shiney again.

Big D · **Joined:** Mon Jun 05, 2006 10:08 pm **Posts:** 349

Funny thing, after I had my O2 sensor changed my mileage dropped 30%. Oh, ya, I also got the BCM reprogrammed.

jcphoto20 · **Joined:** Sun Nov 19, 2006 1:36 am **Posts:** 507

try wrapping 6 or 8 layers of folded aluminum foil around your exhaust infront of your O2 sensors. from what i understand, that will make it run leaner. mine are wrapped all the way to the cat and secured with safety wire. i dont have any header wrap. i get right at 20 mpg driving in the mountains around 4000 ft. on crappy CA MTBE, winter gas

but you cant do anything about the closed loop start up thing apparently.

Running Rich

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