NCLA951

So my new magnaflow 3" CA cat passed visual (Tech, 'good enough for me'), but then the car failed miserably on emissions.

Every fluid and filter in the car is new, new plugs/wires/cap/rotor. It has weltmeister TC8200 chips which in the documentation I found are supposed to be carb eo and good to pass. No other engine mods except LBE and WG shims. Runs only shell 91.

What could be causing these results? Could it be burning turbo oil or is this a running rich scenario? Are the FQS switch settings on the TC8200 the same as factory? Like if it was rich I could set it to -6% fuel?

Car has 108,000 miles, 4000 of which are mine. Was excited to get my CA plates but that will have to wait now.

Thanks,

Sam, 87 951

V2Rocket

i'd be really surprised if any of the old chips would ever pass smog.
you are running rich but it doesn't look like by a whole lot.

high NO means very hot combustion temperatures (from say a lean mixture, but your HC/CO say otherwise)...or a bad catalyst (or just a cat that is not up to temperature to work)

Humboldtgrin

My autothority stage two w/MAF passed with the factory exhaust. Looks like there is no Rhodium in the first part of the catylitic converter with how high the NOx is. I think it's the cat not doing its job right. The other numbers would clean up if they had that extra Oxygen molicual to work with that the NOx is holding. You need to try a differant cat IMO. If you have a race cat installed I dought it will light off without being driven hard. Just to add that's not a miserable test. But the NOx is the problem and the cat probably doesn't get hot enough at 15 and 25 mph compaired to the stock unit. I would find a stock cat and install it for the test. You'll be surprised. Then change it back out.

mtnman82

I would put some stock chips in there and make sure the cat's hot before you take it in, like ~20 minutes at highway speeds. I thought I just read on here to not even turn the car off between pulling in off the highway and having the test done...

NCLA951

I was suspecting the cat as well, mostly because in the location for it in the 3" LR exhaust I have the cat position seems farther back than with the factory set up, with it leaving space to dump the WG ahead of the cat. That far back it doesn't get hot enough on the rollers to work. Some guaranteed to pass, a new O2 sensor for good measure, and a very hot cat before pulling in next time and see what happens.

What chips are people currently using that pass California emissions, or does anyone have a loaner set of stock chips?

Thanks for the replies!

Humboldtgrin

Don't worry about the chips. They don't effect the timing and fuel at cruise, it's when you get on the high boost. I have 20+ year old autothority setup and passed. I would just install the factory cat and take back in for a pretest first. If it looks good, which I'm sure it will, then have it tested officially. But after the test take the factory cat back out and install your 3" because if your car has more power adders it will melt the factory cat like mine did.

NCLA951

Problem is the PO installed the turbo back 3" system, I just installed the Cat into this where the test pipe is. I wonder if heat wrapping the pipe from the turbo to the cat will help get home heat into it? I can't imagine all that NO is coming from over hot combustion, as the engine runs cool if anything.

mtnman82

You're running a stock (K26/6) turbo? pm sent

NCLA951

Yup stock turbo, but have my eye on a 26/8!

NCLA951

Anyone have a stock turbo back cat exhaust in LA area I could borrow for a week or so? Either that or get a thicker subtrate cat of same design and fit that it.

Humboldtgrin

Make sure to get turbo s chips to match the turbo when you upgrade. I don't know if wrapping it will help. That's a small turbo, bigger pipe, further back bigger cat, and cat may be a lean burn CA legal 3" cat without rhodium. Might want to check. Wikipedia has pretty good info on the subject. NOx is formed in high pressure and high temp conditions, internal cumbustion engines, lighting, and not listed is valcano's. But the engine produces the most NOx out of the three. The engine never stops worldwide. Sientist stated if humans didn't drive their cars for a few days then earth would start to repair itself. Personally I think the United Stated Air Force uses as much fuel as all the cars on the planet if not more.

Brantley

I couldn't pass with Weltmeister or Autothority chips... you need to go back to stock chips.

Some regions in CA are more strict than others. LA is an "enhanced" zone so the most difficult to pass in... Here is a map of the different zones -

http://www.smogcheck.ca.gov/pdf/Program_Map.pdf


I'm due for a smog on my green car in January so will be installing my "smog test" cat (DEC mid-pipe) and stock chips some time soon.

Model year '87 is a little more strict for NOx which is some times difficult to reduce.

Some good postings re: smog -

https://rennlist.com/forums/944-turb...g-success.html
https://rennlist.com/forums/944-turb...r-7-tries.html

Rogue_Ant

No.
Welt chips absolutely changed both timing and fueling at cruise.


If you can comfortably touch the tail-pipe on your 951, then it is too cold for emissions testing.

Humboldtgrin

I stand corrected. Noted. And I live in a less aggressive smog area so I luck in that regards. I'm still sticking to the cat not lighting off or not having rhodium which is neccacery to seperate the NOx but has to be above 600f in order to light off from what I remember in smog class, and there's too much O2% in the print out, it should be a lot lower the .7% if the CO is at .62 @15 mph. At higher speeds it gets a little better. I bet if you were going 100mph you would pass.
http://www.smogcheck.ca.gov/FormsPub..._Glossary.html

NCLA951

Joshua are you of the opinion that the chip set may be causing this by over fueling, thus over cooling the exhaust combined with the cat being not hot enough? I have been looking at your chips they seem like a great solution. Problem is 24 pin DME conversion vs daily driver needs. This is actually a good time of the year to have it off the road for a week, how long does it take? Does the A tune have an emissions map? I like keeping the cycling valve and mostly stock boost control set up and AFM, and don't need crazy power at this point (perf expert has me at 270hp which is fine for the moment). Also have a new O2 sensor in the mail to me. Does the A tune have KLR chip as well and can it be set up from you to count in factors such as exhaust size, FPR (I have 2.5bar in now but also 3bar), etc?

Thanks guys!!!