I have seen a couple posts about this but figured I would see if my situation is different. My car has a full header back exhaust and intake. It is throwing a P2096 code "Post Catalyst Fuel Trim System Low Limit".

I tried doing octane booster (I run 93) to see if that would help. It didnt.

Now I tried putting on a mini cat o2 sensor bung on the cat to see if that can help scrub the code. After installation I did the odometer ecu reset to see if that would help ditch the code and it didn't. Anyone know how many miles I need to put on the car before it will trigger the light off?

http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html

The mini dealer said they would only give me a new cat as a fix, and they told me that fixing the cat was the only problem... I asked if they would get rid of the code for me because its considered a "hard code" and I am not sure how else to get rid of it other than miles?

My car currently is not inspected so every time I drive it I risk a ticket...

Thanks for any and all help.

 

First off...
It takes a pro level tool to clear a code like yours... A regular odb2 unit will not clear it.
And the "cluster reset" will do nothing more than reset the guages...kinda like taking off the battery terminal....
Do check for a cracked header or cat...they can usually be welded....

 

Yeah it seems like the dealer wont reset my codes for me using the pro tool.. I checked the header and cat and they look good to go!

 

So it sounds like you don't have a cat welded to the header?
If so...dealer is right...no cat..you are going to have a code, especially on the newer cars, the 2005+ cars are more finiky...
But know of folks running RMW SHORTY headers with a OEM car, many years, no issue and lots of power...not much to be gained IMO going carless. If you still have you cat, it can usually be welded in...not a huge restriction... The idea if an instant 10 HP by yanking the cat is leftover from the terrible cats from the 70's....the modern ones are great, even if you don't go for a low restriction one. Heck on the mini, the harmonics of the motor tends to destroy many aftermarket cats..so OEM is best are most...and most have a free one.

 

Some pics before I added the bigdaddies mini cat o2 bung. I have a cat...

 

Check out the links at post #4 here and see if they may be helpful to you.

 

That is not the code that you typically get from running catless. (P0420 is).

The code that you're getting can be caused by an exhaust leak anywhere before the rear O2 and after the front O2. Exhaust rushing past the leak actually draws a small vacuum of outside air INTO the exhaust system. Start looking for exhaust leaks anywhere between the two O2 sensors.

 

The dealer is "very confident" that this is not an exhaust leak and just an o2 issue... at the dealer now getting my ECU reset.... We shall see...

 

Well that didnt work. Anyone know if putting non-mini o2 sensors on this car would cause these codes to show up?

 

Actually pretty common....think we assumed you had the MINI/denso/NTK UNIT...
BOSH is known for issues, as are some cheap knockoff..
Rockauto has the NTK/denso units for gen1 for $100.79

 

Thanks I just ordered two Denso's. Crossing my fingers that this and another trick can fix it.

 

Good luck. For what it's worth those bottles of octane booster only give you half or one point increase (I know they say 104+ ... That is marketing bs). If you really want to test octane dependence, search for a gas station selling race fuel. It's a linear average - half a tank of 100 added to 93 will get you 96.5 octane...

 

The dealer should be able to tell you with almost 100% certainty if it's a failed sensor or not. Advanced diagnostics are neat like that. However, I can tell you firsthand that a leak of a certain size in just the right place will cause codes like these. It's happened to me, and plenty of others on the "Interwebz". Nobody ever thinks to look for mechanical issues / defects, and jump right to failed sensors.

Good luck!

 

Yes, reading the codes includes stored data should always be first. Doesn't have to be the dealer. Anyone with BMW specific code reader can do it. A copy of DIS/INPA off the Internet will work. AutoEnginuity software will work, etc.

 

where can you get this from please PM me thanks.

 

A Romanian guy was selling it with a cable on eBay a while back...bet he is still around...
Software is basicly pirated....can look on eBay...names change every few months with the listing...
One tip..the odb2 to USB cable is made in 2 versions..pretty minor to hack it if I recall...jumpering one wire if I remember right for folks that could not get it too work...a few threads on this and the BMW boards...
The software is the same dealer stuff...not very user friendly....

 

OK so I have 2 new o2 sensors, I have a custom tune that should increase the acceptable range of gases in the exhaust and I have an o2 spacer with a built in catalytic converter... Just ordered a "BavarianTechDiagSoftware" so that I can clear my own adaptations since the dealer charges $100 each time...

If none of this works I guess I will have to smoke test the intake ( I hear the bypass tube is a common issue) and check the map sensor?... the dealer doesn't think I have an exhaust leak and neither do I, but having my own tool to clear adaptations will allow me to test this a lot faster!

Also the dealer thinks the only way to solve my problem is with a brand new oem exhaust.. which I don't believe them.

 

I've bought from this guy. Still, be careful - I installed it on a junker Win7 laptop I don't use for anything important. Comes with the software and cable. The seller even helped with install problems. Start reading about how to use inpa and dis. This is the dealer software that can do everything ... Even program new keys if you have the patience to learn how.

http://m.ebay.com/itm/252378560285?_mwBanner=1

 

Apparently I need a less free flowing exhaust... So I need to get an oem exhaust for inspections or something like it. Anyone know where I can get one on the cheap?

Thanks

 

How did you decide that?

Can't you just replace one of the flat gaskets in the exhaust with a restrictor plate? Seems easier than changing the whole exhaust..,

 

That does sound easier. Everyone keeps telling me my exhaust flows too freely.... I need something more restrictive. Do you have any more information on a this restricter plate? I will do some googling.

 

If a RMW SHORTY header with a stock cat passes emissions, no lights. It NOT your problem (free flowing).
Look for leaks...like a gasket on the header, a crack in the pipes or a flex joint (very common).

The theory of too free flowing only come cause if you have lots of back pressure, you might not suck air into through a bad gasket ...but it not really a fix...it might take a couple weeks AFTER resetting the code to get the emissions readiness to say ready....
Look for a leak.

 

I am catless and have an o2 spacer, I also have the p2096 or p2098, where the system found lean in bank 2, my problem is that I have a leak in the mid pipe gasket. cat to catback.... I had it sealed up, code went away a couple miles down the road I pushed the silicone out, and code appeared again. and ive just been driving it like that. its a hard code, and will only turn off after start up of not having it been activated.


I initially tried clearing it with my obd2, wont work, and with the car off its not active so I couldn't do it with NCS. but a crack anywhere around the sensor in the exhaust will turn this code on, ill be resurfacing my seals with a new gasket with anerobic or metal sealant and that will work

 

Anybody in the Milwaukee area want to assist in my P2096??

 

Yah just placed my order for it. for the price you can't go wrong. I'm in the I.T. Industry and will be running it on a VM lol. Until i can confirm it nothing malicious in the installer or the code.

Thanks for the link. I just purchase the ECS tuning Tools. I think i will be returning it, if it doesn't clear adaptive or Air bag light/ Codes ect.

I also have this code, but waiting to fix everything first. The joint between the o2 to catback has a little pin hole leak, so I'm about to change everything so waiting.