I knew i had to smog my car so i figured i didnt want to mess around with having to go back so, i put on all the stock Greddy stuff the way it was ment to be exept for the down pipe. I even got a new 3" cat put on. I failed in the NOx by alot, the max is 726 @ 15mph, and 786@ 25mph, but i was 1611 and 1604. What should i do???

 

this was recently covered, reducing nox can be done retarding timing or richening the mixture, both which can have ill effect on hc

 

I just went down to the auto parts store and picked up a new 02 sensor i figured it wouldent be a bad idea to replace it. My timing was set to 8 and stock is 10 i thought?

 

EGTs are too high, richen the mixture if you can and advance the timing.

 

How would i richen the mixture? should i put my 305 injectors back in?? Now ive herd to retard and to advance timing which one is it??? Would wireing my waste gate open help it in any way?

 

advancing the timing will lower egts, but it may make you leaner

 

Ok here is what im thinkin. I will install my new 02 sensor, wire open the waste gate and set the timing to 10 BTDC. So tecnicaly that should be like a stock miata right???

 

Any other hints?? Does any one elce think my idea will work??? Could my cat be so big that the miata wont heat it up. And if so do you think that pulling a wire off a plug and letting raw fuel into it for a few minutes before the smog check would help it heat up???

 

You need to drive the car really hard to get the cat warm. So drive the **** out of it before you go to smog it then leave it running while you wait to get it checked.

 

I too failed in the Nox section about a week ago, retarding the timing from 14 to 8 actually made my #'s a bit worse. I plan on getting my car onto a 4 gas analyzer next weekend and hoping for the best.

 

I drove it pretty hard on the way there and let it run in the parking lot and the smog guy ran it at 2500 rpm for 5 min or so before he smoged it. I just put the new 02 senser in and it seems to run totaly different "good" so ill wire the waste gate open when i go in. I also put stock temp plugs in at the stock gap.

 

God I'm SO glad I don't have to mess with that crap!

 

Hmm, To clarify The guy that advised retarding the timming and richining the a/f ratio is right and will bring down the NOx but raise the HC's What are your other numbers. Giving the HC's and CO's #'s will give us a lil more info to play on.. - Bryan