MX-3.com

My smog test showed that my NOx is double the max allowable and HC is just barely passing while other emissions are fine.

Was told by a friend who is a part time mechanic that the EGR is probably to blame and needs to be replaced. I don't know if he's right... I was thinking it was the catalytic converter...

I figure that little EGR valve/assembly should be easy enough to replace and wouldn't cost much. BUT I can't seem to find one at the local auto parts store and partsamerica.com don't carry it either... what are some of the other online parts store I shoud check? My last resort is probably the Mazda dealer... but think it would cost lot more.

If anyone know where I could buy a cheap one, I would very much appreciate it.

Phil.

The EGR valve for a '91 -'93 with a SOHC should cost you Zero, Zip, Nada. This is due to the fact that there isn't one on this engine. High NOx is normally a sign of elevated combustion temperatures or the catalyser to break down the NOx compounds has failed. I'm guessing that your CO was lower than normal. Hotter combustion temps is a good way to lower your CO emissions but at the some time promote the creation of NOx compounds. You should first look at replacing the catalytic converter and than have the fuel injection inspected because the only thing that will make the combustion that hot is if were burning extra lean. In the catalytic converter it is easier to deal with CO compounds than it is to breakdown NOx compounds this is why this if anything this engine should run a little rich.

No EGR... ahh.. ok..

And yeah, my CO(%) is pretty low at 0.13(15mph) and 0.01(25mph). My HC(PPM) is near failing at 125(15mph) but 33(25mph). NO(ppm) is my problem... 1916(15mph) and 1114(25mph). That's amost double the Max allowable heh.

Thanks for the input Yoda. You da man! =) Will change out the CAT and go from there.


Phil.

oh yeah, what about the Oxygen sensor(s)? Is there just one or 2 on my 92 1.6L 4cyl Mx-3? should I go ahead and change it/those out too?


Phil.

wait a sec... while looking at the Online Shop Manual, I see on page F1-133 that there is the EGR Valve! What's the deal Yoda? Did the Dark side cloud your judgement? hmmmm? =p


Phil.

just an fyi...I've heard good things about car-part.com for future reference...

Prexus2005 wrote:wait a sec... while looking at the Online Shop Manual, I see on page F1-133 that there is the EGR Valve! What's the deal Yoda? Did the Dark side cloud your judgement? hmmmm? =p
Phil.

That pg. of the online manual is for a 1995 B6 DOHC motor. Your's is the earlier B6 SOHC right.

will check car-parts.com thanks. =)

Yes, mine is 1992... so I really don't have an EGR? Any idea if I have just one Oxygen sensor or do I need to order 2? Thanks.



Phil.

there is only 1 oxygen sensor!!

Thanks Joey. 1 Oxygen sensor and 1 CAT to order. =)

Car-parts.com didn't even list those parts so I'm going back to partsamerica.com.

Thanks all.


Phil.