Cal Club Autocross Forums

Hello everyone,

I acquired a 97 Civic previously owned by Kai Hur. However, I can not get it to pass emissions. It's failing NO at 15 MPH test. It's posting 553 PPM when the max allowed is 487 PPM. Is there anything I can do to fix this? Or is there a racer friendly emission test center somewhere close to OC that will help me pass it? Thanks.

Simon

Retarding the timing on a Miata will shrink the Nox numbers dramatically, but I don't know about Hondas. I've also used CRC "Pass or don't pay" fuel additive for the same issue. The smog tech couldn't believe my re-test numbers- he actually told me that I must be "a really good mechanic." Ha.

Our Miata will need to be smogged soon. Our check engine light has come on. 97K ... hate to have to buy a new CAT. Anyone know where to find the engine light re-set device? Although if we need a new CAT, perhaps that's what our tired engine needs!?

Mako Koiwai wrote:Anyone know where to find the engine light re-set device?

Take off positive battery lead for 10 minutes then put back on?

Mako Koiwai wrote:Our Miata will need to be smogged soon. Our check engine light has come on. 97K ... hate to have to buy a new CAT. Anyone know where to find the engine light re-set device? Although if we need a new CAT, perhaps that's what our tired engine needs!?

rent it from autozone for 10 minutes.

I have an OBDII scanner from the great ST* clarifichange (love that word) of 2007. I never could get my WRX in ready mode, even after 1000 miles (all autocross!)
I know it's far, but if you want to use it, you can.

I think my Scangauge II will clear codes on an obd2 vehicle. Pasadena is closer than Corona for you. But I've gone to autozone a couple of times and used theres. sure most chain stores loan them. No charge at autozone to try it in the parking lot. They keep your DL.

Christine Berry wrote:

Mako Koiwai wrote:Anyone know where to find the engine light re-set device?

Take off positive battery lead for 10 minutes then put back on?

Tried that once. The light came back on before the test was done. Despite the fact that all my readings were well below the max, he failed me.

Mako Koiwai wrote:Our Miata will need to be smogged soon. Our check engine light has come on. 97K ... hate to have to buy a new CAT. Anyone know where to find the engine light re-set device? Although if we need a new CAT, perhaps that's what our tired engine needs!?

Have you searched on miata.net for the answer?

Not sure about the Miata, but if you disconnect the battery or use a device to clear the code, the car won't go back into ready mode until some set period (x number of starts, miles, etc...). And if you're not in ready mode, you won't pass smog, regardless of how the rest of the test comes out.

If you're going to get a new cat, I'd install it, reset the code and then drive it around for a week or so...

Not sure which year is your Miata but on my 95 you can use paper clip to reset the code on a connector box in the engine bay. Once code is reset just drive it around a while and take it to emissions.

However, we wonder off topic a bit, anyone got ideas for me?

Sorry Simon

... did you read what someone said below about a fuel additive?

If you don't correct the reason it set the code in the first place, the check engine light will come back once the ECU is back in ready mode. I have the same problem with my F150.

Mako, I have a OBDII scanner you can come by the shop and we'll reset the light, but no guarantee it won't come back on again.

Mako Thanks, I did read that. I'll give that a try. Hopefully I can finally register the car and be able to race soon.

Simon Lu wrote:Not sure which year is your Miata but on my 95 you can use paper clip to reset the code on a connector box in the engine bay. Once code is reset just drive it around a while and take it to emissions.

However, we wonder off topic a bit, anyone got ideas for me?

High NOx is usually either a bad EGR or timing advanced too far, both things causing high combustion temps which causes high NOx. I don't know if the timing on your Civic is adjustable? Maybe Kai was looking for a few free HP? ;) Seems like if it was the EGR, it would throw a code.

Regarding Miata CELs (or any for that matter), you really can't do much until you get the code read. Yes, disconnecting the battery (then pump the brake pedal a few times) will reset the code and I suppose that's worth doing, but when the light comes back on you have to know why. It could be as simple as a bad gas cap. Take Steve's advice and go to Autozone or I think Aamco or Midas will also read the code for free. On a Miata, there are many reasons for a CEL and believe it or not, that little computer is pretty darn good at telling you why.

Pat.