Need aircare help!!

[martin vanderwel]

Failed aircare 3 times now. Yeah you think i'd get er figured after the first, I know. Anyways my co2 is fine, its the hydrocarbon. Im allowed 110, and I'm around 186. How can I lower it, just I can pass aircare and then I can change it back to normal. Racing greed did all the tuning on the dyno...runs good, fails aircare though

[Marke Bailey]

How new is the cat? What are you using to tune with?

[Paul Pigar]

I think he's tuning with dsmlink v2. Did u try running with methy hydrate? I think your cat is taking a shit .

[Tony Leong]

My Talon failed Aircare's NOx and HC (for 1992 and above emissions specifications) levels with an old, high-flow cat and Methyl Hydrate in the gas tank.  Bought a new high-flow cat, went for an hour's drive with a full tank of Chevron 94 (I always run C94) with no Methyl Hydrate, went straight to the Aircare Test Facitily and passed.

What works for me might not for you.  Good luck on troubleshooting this one.

[martin vanderwel]

yeah im using dsmlink v2.5, and the cat is fairly new. before i got it tuned, it was running pretty rich. do you think that played a part. can't i just set the timing back a few degrees or are we thinking its gotta be a cat problem?

[Brett Haviland]

back the timing back??  i dont think that will help your failing HC.  your either going to have to lean it out some... maybe even add some timing if ur NOX isn't too bad.

did u get ur cat really hot b4 going thru?

[martin vanderwel]

yeah sorry, i dont know what I was thinking on the timing part. Anyways I did get my cat nice and hot (i thought anyway) ran it for a while before and kept the rpms up a bit. I leaned it out 1 full turn on my afpr, and i can tell its leaner because it doesent drive as good. still didnt seem to help

[Brett Haviland]

just take it to a shop... they can check to see if the cat is doing its job in the first place.

If you are near aldergrove i can take a look at it for you at Cromptons Auto Care on 276th.

[John Hartman]

removing timing does definately help with HC.  But you can't take out too much, because then the car is a slug and the aircare driver has to push the gas pedal too hard to get the car to accelerate on the dyno.  Then it goes into much more aggressive maps and open loop.

HC is also caused by misfires and cabon deposits on the pistons.  HC is rarely caused by overly rich mixtures.

But if your car is not average in its readings or better, there is something wrong.

Make sure the car is in closed loop, make sure everything is in good order, make sure its set to correct base settings(timing etc).

You can also raise the idle a tad, but not over 1100 or they won't test it.

If you have no EGR and or big cams, it can be tricky, especially with a 92+ car.  Also higher compression ratios can be trouble on failed or close to failing NOx readings as our cars(1g turbo) are 7.8:1 compression and therefore the calibrations in the aircare system are for low compression.

And the other thing about a cat, even if its fairly new, if you have been dyno tuning on it or racing on it or even lots of aggressive hill driving with the tune very rich, you will kill the catalyst very much quicker than it should.  Like weeks instead of years.  

Also if you drive with a misfire for even a few hours(minuits even with a bad one under heavy load) your cat will loose probably 70% of its efficiency.

[Tony Leong]

Good call Brett on getting an Aircare cert'd shop to do a diagnostic.  Aircare gave me a brochure about what to do when the car fails.  I looked up the repair centres and picked the first one listed for my area.  I spent $95 plus tax for the diagnosis.

When I was doing my research for failed Aircare, I came across a comment from a BC DSM member that his cat was about six months old when it failed Aircare.  Running rich could have damaged the cat's innards, so that it semi-thermo/chemically reacts with the exhaust gases, but not enough to meet emission standards. 

A high-flow cat has less of the catalysts (provides less restriction and less ceramic/platinum keeps costs lower than a factory unit), such that even a lightly loved cat could fail your DSM.

[daniel Dee]

+1 thats good infro on the cat...I better remove my walker cat  (air care passed) right away before driving around too much..

[John Hartman]

Tony, a good modern high flow cat will have lots of catalyst substrate in it.

In fact it may have more than a cheap brand of lower flowing cat simply because its bigger.  Some of the cheapies are only about half full.  The first and last bit of the shell is just open space and on top of that, they are wee tiny. 

The magnaflows and walker "supercats" that I have used are usually at least 3/4 full and are much bigger than the cheap ones.

[martin vanderwel]

yeah im sure its my cat. I know the guys at Greendale Motors in chilliwack and kept testing it there. Raised the idle a bit, and hope to bring it to aircare tomorow with positive results. But yeah my cat is probably on its way out, so were trying to compensate anyway we can. wish me luck!

[Tony Leong]

Tony, a good modern high flow cat will have lots of catalyst substrate in it.

In fact it may have more than a cheap brand of lower flowing cat simply because its bigger.  Some of the cheapies are only about half full.  The first and last bit of the shell is just open space and on top of that, they are wee tiny. 

The magnaflows and walker "supercats" that I have used are usually at least 3/4 full and are much bigger than the cheap ones.

Good point John.  My 2008 high-flow cat was a no-name brand from Buscher Racing.  My 2011 Vibrant high-flow cat has a substrate that touches all the walls inside the cat.  Looking through one end of the cat through to the other, the only light I could see were via the numerous, tiny little holes bored through the substrate.  However, the substrate does not occupy 100% of the cat's interior chamber; there's empty space in there.

The Buscher cost me about 50% more than the Vibrant.  And I assumed spending more $$ would get me a better quality cat!

Knowing what I now know, I retract my statement, "A high-flow cat has less of the catalysts (provides less restriction and less ceramic/platinum keeps costs lower than a factory unit), such that even a lightly loved cat could fail your DSM."  My own experience was that my factory installed cat lasted thirteen years and my high-flow lasted less than two.

[John Hartman]

hehehe, yea thats a bit odd.

Factory cats often are pretty bad ass tho, especially the older pellet style ones, they had a lot of goodness inside.

A cheapy no name universal cat for a small car will get around $5-$10 from the metal scrap guys, whereas an old pellet cat can fetch up to $60-$80!