Can not pass emissions
 

Its a 1987 420 SEL and the only thing that it did not pass emission on

HC (PPM)
Cruise Limit 150
Cruise Emissions 209

What do I need to do to fix this. I did change spark plugs. Any help can be helpfull.

Rob C
Seattle

87 420sel
 

what kind of test do you have to pass in seattle?how is the mpg on your car? when was the oil last changed?when were the plugs last replaced?how old is the o2 sensor?

Only 1000 Miles on the Oil change. O2 Sensor is 1 year old. Spark plugs are brand new.

emmissions
 

do i see that this is just a two speed idle test without the rear wheels being on a dyno?

This was on a rear wheel Dyno 2500 RPM speed and Idle.

http://www.emissiontestwa.com/

emmissions
 

ok,at idle we have very low co and at 2500 the co jumps to .41.this would normally mean that the o2 sensor was not controlling the mixture.you said new o2 sensor so perhaps over voltage protection relay not working properly.i asked you about mpg and this is important to see whether car running well or using lots of fuel.

Sorry about that 16 miles per gallon

I did check the Overload Relay and the Fuse is in good shape and I did check the Connections by looking at it.

emmissions
 

ok so have to assume that car is just running too rich when you step on gas[beyond range of o2 sensor to control] or........catalytic converter is weak.

Ok how do I fix the O2 sensor to start with. I do blow alot of grey/blueish smoke when when the car is under alittle load or going up hill.

What do you think I should Do. I may have the tools to work in the car but i love to see what you think I should Try.