ClubRoadster.net banner

141 - 160 of 186 Posts

·
Registered
Joined
·
169 Posts
Did you happen to pass smog? Please reply and let everyone know how you did and let us know what you did to help pass.
I haven't done my smog yet seems this is the plan
Oil change spark plugs adjust timing 91 octane oem header cat n oem exhaust 30 min drive:hello kitty:
 

·
Registered
Joined
·
459 Posts
I failed today :(

Looks like its way above average on all counts, so it might be hard to pass. Think I can just run it hard for a while and try again ?

What do you guys think needs to be changed based on my failures ? Its a 94 by the way.

O2 sensor? New cat? Being in Cali, can I buy any cat and have it welded on ? Id hate to spend money on a stock cat, if I can get a high flo cat so later on down the line it can help when I get an exhaust system done.

And last buy not least, I can get a hookup if these things are gonna cost hundreds of dollars.

Thanks for any input !
 

Attachments

·
Registered
Joined
·
459 Posts
Alright, new Cat it is.

Being in smog nazi cali, are there only certain types I can buy ? Or anyone know a good place online to buy one? Whats an average price to pay for the Cat, price for install ? Any Hi Flow cats that I can buy for my car ? I sort of plan on getting an exhaust on the car at some point, so knowing that, what type should I get ?

One last thing :D

Should I just replace the oxygen sensor while I am at it ?

Thanks CR, youre not all hellaflush ricers, some of you are full of useful knowledge !

Edit: I guess I am asking about size, what is the size I need, and if im planning on getting an exhaust upgrade later, can I get a larger size now ? Or if I want larger size, do i need new exhaust and new cat installed at the same time?

Im thinking Racing Beat sounds nice, not too loud, im too old for too loud :p

:D
 

·
Registered
Joined
·
459 Posts
MagnaFlow has a few cats and they seem pricey, are these " performance " cats? Does that even matter or is a hi-flo cat a waste of money?

http://www.amazon.com/MagnaFlow-California-Pre-OBDII-Converters-1994-1995/dp/B0058PAMRS/ref=sr_1_3?s=automotive&ie=UTF8&qid=1356600156&sr=1-3&keywords=36696 This is a direct bolt on.

This is Universal
http://www.amazon.com/gp/product/B001P9RXX2/ref=ox_sc_act_title_1?ie=UTF8&smid=ATVPDKIKX0DER

$207 and $350 dollars respectively. More expensive one will bolt right in, I can do this at home, Universal will need flanges and a shop to install.

:/

Any other options ?
 

·
Registered
Joined
·
623 Posts
my '99 failed smog today. Has 01+ header, roadstersport 3 mid pipe (w/ high flow cat), and stock intake.


im going back to stock midpipe (which passed 2 years ago). I have a question though, does the o2 sensor after the cat affect the numbers?
 

·
Registered
Joined
·
194 Posts
Im pretty sure all 02 sensors can affect the numbers. I was in the same boat as you are a few months ago, problem ended up being a clogged O2 sensor due to Seafoaming.
 

·
Registered
Joined
·
300 Posts
Just failed my state-referee smog.

from what I've read, I think I just need a new CAT. But the significant drop from 15-25mph in NOx is making me think the CAT works fine. I'm also borderline on HC at 15mph..
I just put on stock header, stock cat (not sure if it's been changed) and my o2 sensor has only about 10k on it. Gonna definitely do plugs and cables/oil change. I also set my timing back to 10 degrees yesterday.
The car was driven for an hour and a half before the test, but sat for 45 minutes until the test was done, could it have been too cold still? Next time definitely leaving it idling until the test.. suggestions?
 

·
Registered
Joined
·
300 Posts
So, after a spark plug/oil change, timing adjust, and fixing my purge valve that was malfunctioning, I had it tested again this morning. Except for this time I failed worse. Now it's a gross polluter. At 15mph, Instead of 1745 in the nox its above 2400 now. The HC is also failing now too. But everything passes at 25mph... WTF. I also drove the car for 2 hours to get to the place and had it running the entire time, so the cat was definitely hot enough.
I'm stumped but I'm guessing my next bet is to buy a new cat. I might just take it to a shop to be diagnosed, I'm tired of not knowing the real problem. I hate California's smog laws.
 

·
Registered
Joined
·
83 Posts
I ride dirty as hell, my car smells like a diesel going down the road.

Header
Full EGR delete
Test pipe (no cat here)
Timing advance

Hasn't been a cat on my car in years, fails emissions every time. Phony receipt for $300 gets me new stickers every 2 years, but hey Ohio's a lot easier I guess.

Sent from my XT907 using Tapatalk 2
 

·
Registered
Joined
·
622 Posts
So, after a spark plug/oil change, timing adjust, and fixing my purge valve that was malfunctioning, I had it tested again this morning. Except for this time I failed worse. Now it's a gross polluter. At 15mph, Instead of 1745 in the nox its above 2400 now. The HC is also failing now too. But everything passes at 25mph... WTF. I also drove the car for 2 hours to get to the place and had it running the entire time, so the cat was definitely hot enough.
I'm stumped but I'm guessing my next bet is to buy a new cat. I might just take it to a shop to be diagnosed, I'm tired of not knowing the real problem. I hate California's smog laws.
What year miata? Judging by the 4xx nox at 25mph and 1000+ nox at 15. There is a good chance its not the cat. If it was 1000 25 and 1000 15, then there would be a better possibility it is the cat.
 

·
Registered
Joined
·
300 Posts
It's usually the covnerter with high NOX. When was the last time it was replaced?
I've never had it replaced, but idk if it's the original one..

What year miata? Judging by the 4xx nox at 25mph and 1000+ nox at 15. There is a good chance its not the cat. If it was 1000 25 and 1000 15, then there would be a better possibility it is the cat.
It's a '91. And that's what I'm thinking too, which is why I'm stumped.
 

·
Registered
Joined
·
1,155 Posts
Got a question. Recently I got smogged. The shop was star certified(the new gold shield) as well a test only. I got the tail pipe tested as well. What gives? I thought 2000 and up OBD2 would be only visual and computer?
 

·
Registered
Joined
·
33 Posts
My car failed smog with high HC and CO (both marginal). NOx was fairly low. The car is running rich beyond a doubt, the HC and CO numbers are corroborated by terrible gas mileage (19mpg) and the smell of unburnt fuel.

I've changed the O2 sensor with apparently no effect. Does anyone know how to adjust the AFR on a stock 1.6L? Plugs, wires, and thermostat are next but irrespective of throwing money and parts at it, I'm curious what the actual problem is.
 

·
Registered
Joined
·
33 Posts
Ok so I threw more money and parts at it. Changed the spark plugs, wires, and thermostat. Apparently I shouldn't have. Failed again, and moreover all three readings got worse.

Here are the initial and latest (today's) numbers:



The car runs terrific; idles well at 850rpm and the timing at 12 deg. BTDC shouldn't be an issue either. Where do you guys recommend I throw money at next? Cat?
 

Attachments

141 - 160 of 186 Posts
Top