Help with emissions

[moomoomoo]

My car is running really rich right now and I won't be able to pass my emissions test because my HC reading is way too high.

Right now I'm running a fairly stock setup. I don't really know too much about engines but I do know a bit. My spark plugs and O2 sensor are all black which i learnt means my car is running rich. Here is a list of things that might be affecting that, so please, if you have any suggestions please help.

-im using a maf sensor from the ca18de pulsar-02 sensor from the ca18et 200sx, mounted on my custom downpipe-spark plugs I'm using are the ones listed in the "crossover parts thread"-i have a 1g dsm bov mounted on my custom 2.5" UIC, vented to the atmosphere-i have a hi-flo cat-2.5" catback-i was also informed that the wiring for my engine could have been done incorrectly and that could cause it to run rich, but i highly doubt it

so if anyone has ANY input as in to why my car is running rich, your thought are greatly appreciated

thanks for your time,Jerry

[xyster]

I had my car emissions tested, and it failed for slightly high HC too. I'm going to try tuning it ever so slightly lean with an SAFC, and turning the boost way down when I get it tested for real.

That atmospheric bov could possibly be making it run rich, tho.

[Notchbackca]

stock map is really richso if you don't have a way to lean out, make a few vacuum leaks before being tested, and get some new plugs too

[nab911]

Couple things. The high flow cat wont help much with HC but it will lower it maybe slightly but its mostly your NOx gases. Are you blowing black smoke? Try running some pass emissions and fuel injection cleaner and possibly replacing that o2 sensor.

[moomoomoo]

Okay so here's a list of things I should do then-turn the boost down-put the stock UIC pipe back on so that I'll have no BOV-get new plugs-already got a new 02 sensor the other day-use some injector cleaner

and yes, my car does blow black smoke from time to time, not big clouds of it though

do u think putting a stock cat back on would help? nab911: from your response, I'm getting that the high flow cat is actually LOWERING the emisisons #s?

any other suggestions would be greatly appreciated.thanks

[xyster]

sorry to dig up a nearly dead thread...

my 92 coupe w/ CA18 passed emissions today, with no special tuning. It's mostly stock, except for the greddy vspl fmic. I'm running about 9 PSI with a hallman es manual boost controller, and no BOV. It has a 3" exhaust with a carsound hi-flow cat. No charcoal canister. My HC reading was 58ppm, which easily beats the limit of 132ppm. If anyone wants, I can scan the results.

[nab911]

wow makes me feel kinda good... but now i gotta think about getting flanges welded when i get my custom exhaust made so i can put a cat up at emmissions time instead of a test pipe. And mom sorry i worded everything wrong but i meant to say putting the normal cat back in lowers nox gases but definatly get that thing tuned and it will balance your a/f out and make it not run so rich so u can lower you HC's (fuel emissions).