Ok, well when I first got the car it was all messed up. I've done a lot of fixing. Before it was spitting out 430 HC and 0.95 CO. Had barely any boost and bubbling coolant, and a lot more. This is 30k engine with 120 psi each rotor. So I knew it had potential. I fixed all the problems, did a tuneup, and threw in a used 100k+ miles factory catalytic convertor. And here is the results:

15mph
HC: meas= 100. Max= 88 fail
CO: meas= 0.07. Max= 0.52 pass
NOx: meas= 115. Max= 704 pass

25mph
HC: meas= 71. Max= 53 fail
CO: meas= 0.06. Max= 0.50 pass
NOx: meas= 90. Max= 738 pass

My mods:
pfs intake and smic
racing beat catback
3" downpipe
Mazda factory cat (100k+ miles)
J&S knock control module.


I think the numbers are pretty good. And I'm pretty close. I'm thinking of messing with the timing a little. Advance it a bit to bring down the HC since I have plenty of space for NOx to go up. If that doesn't work, I might just buy a new factory catalytic convertor but that's $1300. Ridiculous amount that I don't have right now. How long does fd cats usually last? I hear about 100k miles. Lmk what u guys think. I want to get smog over with, so I can start modding my car the way I want it.

 

My FD just passed smog with a 160,000+ mile cat that I think is original. My car originally failed the pre-test because the 25mph test was failing. I got a new O2 sensor and my car passed. My mods are: HKS downpipe and a cat back. Search for my smog thread for some things to check. Theres some good replies in there.

 

Hight HC usually means the motor isn't burning clean, have you changed out the plugs?

edit: Do an oil change as well sounds goofy but it helps

 

You're real close. Stock ECU on your car? In any case, I would clean the air filter(s), change your oil/filter, and check/change your plugs for stockers (run 7's leading, 9's trailing). And check your O2 sensor, as per Wan

 

what ecu are you running? sounds close to my problem. N3a1 for Cali or n3a3 for everwhere else. Also did you at least drive the car 20 miles before you brought it in. Because if you don’t heat up your cat enough. The beryllium metal will not ignite the left over fuel from the eng. Do not turn your car off before the test and let it idel.It almost like a toaster oven you have to heat up the element (THE CAT) before it can cook!

 

Stock ecu n3a1. Ngk platinum spark plugs with 25000 miles on em. I did an oil change 2500 miles ago, it's due. Brand new rx7.com o2 sensor with less than 300 miles. I'll do an oil change and probably change the plug wires. The thing I forgot to check was the ignition timing. I really need to do that. When I tested, I drove about 10 miles after warming up and then held the throttle for 5 min at 3000rpm. Next time I'm going to drive 20 miles and then hold 3000 rpm for 10 min. I want to burn every ppm of hc as I can. Any other suggestions?

 

Force 13B gives excellent advice.You could also ensure your air filter(s) is clean.