failed emisions

[scotta123]

1990 cady fleetwood base model first test
hc:0.6
co:27.2
nox:2.67

replaced spark plugs, wires, map sensor, pcv valve, engine temp sensor, throttle position sensor, oxygen sensor, cleaned throttle body, and replaced worn vacuum lines

got emissions down to
hc:0.61
co:20.95
nox:2.67

i needed to get them under these numbers
hc:1.0
co:12.0
nox:2.5

i dont know where to look im not good with emissions any suggestions

[MagicRat]

I am no huge expert on emissions either. But I suspect since the HC are within limits your engine is burning the fuel efficiently.

The high CO indicates a catalytic converter that is not functioning properly and the high NO means your EGR system may not be working properly.

[danielsatur]

How old are the catalytic converters on this car?
See http://www.catalyticconverterwarehouse.com
Make sure car is at normal operating temp, when doing the emission test.

[scotta123]

if the cat is bad it is not plugged up but i would bet it is original equipment

what all is part of the EGR system I know the Egr valve was replaced last year

does anyone know 1) how to tell if that cat needs to be replaced and 2) where i can get a vacuum tube diagram to just go ahead and replace all the vacuum lines

thanks for the help so far

[maxwedge]

Egr is a system that directs some exhaust gas into the combustion chamber this reduces nox, the cat also helps in this process, make sure the egr works.

[danielsatur]

OBDII systems has a down stream H02 sensor to tell the ECU/PCU if the catalytic converter is working, however if plugged it doesn't.
Your car has OBDI system,
Any muffler shop should beable to test your catalytic converters.