My side of the street has been annexed into Memphis, YAY. So I decided to take noisy in for inspection this morning because I will need a new tag in August and am wondering if my exhaust will pass inspection and guess what? Yep failed. So now I’m trying to decide what to do next. My mods are in my signature.


My first thought is to try the inspection with the original tune file. I really don’t think this will make a difference but it's couldn’t hurt. The other painful thought is to put my stock downpipe back on.

Looking at the stock cat it almost looks like I could cut the ends off and weld it up to a 3" downpipe. I wonder just how restrictive the stock cat minus the second cat would be compared to the two high flow cats.

 

you do know that you failed the hydrocarbon section right? hydrocarbons are flammable, in your case its probably gasoline... the cat converts co to co2 (which its doing fine and efficiently) but is not converting the hydrocarbons well. remember, most cats require at least 30 minutes of the engine running to get the substrate hot enough for the catalysts to do there job ans since the hydrocarbon part is actually just a combustion reaction, the cat has to be REALLY HOT! since yours is a high flow one in order to get e gasoline in the exhaust up to ignition temp (well.. hopefully not ignition temp as that would be too fast and would cause a backfire, but hot enough so the combustion reaction occurs quickly enough converting it to c02 and water).
this is the main reason why if i start my car and crank it in the morning i can actually smell gasoline, but after its been running for a while you cannot smell it anymore.

 

So you think swapping back to the stock tune will be the fix? My AFRs seem to be the same as with the stock tune at idle. I did notice my EGT went down because I was waiting in line so long (from 1300F to 950F) so maybe that caused the hydocarbons to be high. I am still wondering about putting the stock cat back in by cuting the ends so that it welds up to 3 inch tubing. The P0420 code bugs me and makes my wife think I messed up the car, which I guess I did.

 

Here's a thought... if your catalytic converter is not getting hot enough, temporarily restrict the exhaust flow so it's not moving by it so fast. Perhaps just put on a temporary exhaust tip that's smaller.

 

jumping jack got mroe at what iwas saying. the cat has to reach a certain temp and have enough back pressure to do its job correctly. id swap out ot a different cat or some how restrict the exhaust.
as cats go remember to get a metalic core one for our cars, it should work a lil bit better. i have a metallic core (not semi-metalic) spun pacesetter cat from summit racing on mine.

 

You could also lean it out slightly, I know I guy who does that for his turbo RX-7 when he does emissions. They just have you idle your car right?

 

Yep, how could I get it to run lean?

 

It's your down pipe, you are going to have to put the stock one on to pass ( my opinion). You should also flash back your stock tune.

I'm in California and we have visual also, so I have all of my stock parts to put back on.

 

Run the stocker for the inspection the switch it back. Done and over with I had to do that for my Spec V when I was running catless.

 

Ruining catless!!!! Of course you will fail, and should get a big whopping fine for doing so. It is strictly illegal in all 50 states. BTW cats also convert NO2.

To the OP, It is probably only the tune that is making it run a tad rich. These things run really, really lean. So to get more power, it is probably tuned far richer. You need to flash it back to stock, test, and then put your tune back in. Might talk to your tuner. A tune that causes you to fail emissions is ILLEGAL. They may not have compensated for all of the other mods you have done.

 

I suspect the tune has nothing to do with failing, but rather the lack of a good catalytic conversion process (aka crappy alta cat)

 

Maybe try again but try doing what you can to make your engine burn the fuel more efficiently, and run her around for a while before the test to warm up the cat. As a rule, I always run my car for at least 1/2 hr before having an inspection done.

Tune actually makes your MINI burn the fuel more efficently. Esp if you are running larger injectors. Cant read that doc very well, how far behind the state's bench mark are your measurements ?

Are the plugs air filter older/boarderline ?
Ever run the seafoam thru her to clean out the carbon buildup ?

Both may help.

 

Clearly this is his racetrack only vehicle, if it wasn't and it's illegal to run catless, that would be a violation of site guidelines and all the catless posts and discussions would be removed.

 

Clearly it is also illegal to park left wheel to curb too as I have seen in some pics. So what's your point krim ?

Excessive speeding is otherwise unsafe and arrestable. Therefore looked upon a bit differently. Which is why we have such great modderators here who have the ability to know the difference, to recognize the spirit of which the guidelines were formed, and the courage to follow through when duty calls......

Motor Safe.

Dave

 

"Tune actually makes your MINI burn the fuel more efficently"

Wrong! The goal of a tune is for more power. More power comes at a less efficient air-fuel ratio. About 12 to one or so.

The OP was commenting that he failed emissions test. Therefor, it can be assumed, maybe incorrectly, that this question was for a street driven car. Emission tests are not needed for cars driven off-road only and hence are not licensed for the street.

 

HAHAHAHA Can you pat yourself on the back anymore?

If anyone wants to run catless and speed they can as long as they can pay the fine and or do the time. I have no problem with what others do.

This is still a free country unlike the NAM last time I checked.

 

Typically you would just open your tuning software and change the pulse widths.

If you dont have a cat on right now the quickest way to pass emissions is going to be to put it back on (assuming you still have it).

 

I put a winky at the end of the comment and I will leave it at that. I moderate on other forums, so i know when to shut up when called out by a mod.

 

"Typically you would just open your tuning software and change the pulse widths."

Wrong again. Not if the ECU is working. Your AFR is set by a CLOSED LOOP system. Target values are set in the tune. The ECU calculates the pulse width based on several parameters, e.g O2, MAP, temp, RPM, TPS, gear, etc. Only cold start for 15 seconds or so is fixed.

 

+1 to the tune NOT being the problem. Stock tunes run extra rich to make sure there is no detonation. Extra fuel also acts as a cooling agent in the combustion chambers.

Running rich normally only applies at WOT. The OBC is designed to attempt to maintain a 14.7:1 A/F ratio up to 80% pedal. At WOT (> 80%), the OBC quits monitoring the system and just throws all the fuel it can at the engine. Even then, this percentage can be capped. When I datalog my computer, at WOT, the software says 88% open.

Sorry, I don't know what the stock A/F ratio is for 2nd-Gen MCS'. I know that the stock ratio for 1st-Gens is < 10:1, which is very rich. A properly tuned boostfed engine, regardless of the power adder, should be around 11.5:1, give or take. Even if you have larger injectors installed, the tuner would make sure this ratio is the goal. So long as there is no detonation, and the exhaust temperature is not too high, you should be good.

Also, if I am not mistaken, the tune modifies only the WOT circuit, so you should not see a difference in EGT temperatures at just idle.

...

Go back to soccerbummer1104's previous posts, as well as mine.

 

Good points, IF it only effects WOT. Not sure of every tune. There is so much "range" left on the table in stock tune, some tunes are more aggressive throughout the band.

So, if the O2 sensor is good, the tune does not change the target for idle, or wherever it is being tested, then it is the lack of a cat burning up unburned HC that is the problem. Put the stock cat back on.

 

Thanks for all the recommendations. What I decided to try first was putting the stock tune back on and doing my best to heat up the cat plus make sure there was no line to wait in to have the car tested.

Yesterday around 4:00pm I checked the DOT site and there was only one car in line so I decided to leave work a touch early and give it another try. I put the stock tune back on and drove to the inspection site in 1st and 2nd only. It's only a few blocks from my office so I had to drive around a bit to get the exhaust temp up. It was about 200 degrees hotter for this test than the first and I passed.

The test showed only .02 CO and 122 HC. My personal feeling is that it was the cat temp that made the difference and not the tune.

 

Glad you passed.

 

+1 to the downpipe comment,

I too live in California, -we have pretty restrictive smog laws out here.
I have a larger intercooler and CAI mod' ...I know that the intercooler isn't an issue for the visual portion of the test (as you can't even really see it and most of the people doing the smog tests wouldn't even know to look for a larger intercooler), ...my only concern is the CAI. I have the DDM version, which is basically a K+N air cone style airfilter on the end of a tube. I've seen that many car manufacturers offer a similar style as an after market part (I believe Lexus actually does), ...any knowledge if the smog testers will go ape poop if they see a CAI on my MINI? -guess I could just put the stcok one back on for the test though as it's a quick removal.

 

In my experience, (not with the MINI), yes the smog people will care about the CAI.

Though, I have also heard it depends on the place you go. Chances are though, going to one of the places without them knowing you, they will likely care. Unfortunately, they like to run stings on SMOG shops to be sure they aren't letting things slide through.