Failed Emissions test.

[mazda626-1]

said my HC(ppm) was 170, when standard was 146 or less...
also my NOX(ppm) was 3692, when standard was 1134 or less....
any ideas? i thought maybe cat converter, or egr , ... but the guy at the shop said if it was the converter, ALL the emissions tests would have failed, not just the hc, and nox....
help please. im broke as a joke. would like to hopefully fix it myself instead of paying some guy to rip me off..
thanks.

[Jpit]

I would start at replacing your primary O2(Oxygen) sensor, your spark plugs and air filter. If you do it right you can do the whole thing yourself for about $75. If you have an Autozone around you you can buy the O2 sensor there and they will loan you the Slotted socket set for FREE. You have to put down a deposit but when you bring it back they give you your money back. Plugs are cheap, about $10. Air filter the same.

You are right in thinking the EGR valve but they can be expensive to replace. You may be able to remove it and clean out the ports on the intake manifold where it mounts. Replace with a new gasket.

Let me ask you this. How did they check your emmisions that failed? Was it by connecting into the Connector inside your car under the dash or did they stick the wand up the tailpipe? If they connected into your connector under the dash then you may have to replace the second O2 sensor on your car(if the '93 had a second one). The second one determines your catalytic converter efficiency. (at least it does on '96 and later years). Good luck.

[mazda626-1]

they put that wand up the tailpipe..

[Jpit]

You may want to try just cleaning your EGR ports and if you replace your plugs make sure to go with the reccomended NGK's. Some people have had problems with other plugs burning hotter which leads to higher nox levels.

[tommaz626]

great stuff guys, this is the info i was lookin for, and, does anyone know where to download a mazda 626 '93 owners manual?