420 SEL with 560 motor major emissions fail
 

I moved from NY to California this year and just tried to smog my 420 SEL with 560 motor and failed by a huge amount. Readings are:

HC (PPM)

idle: Max=120 measured= 455
2500 RPM Max=140 Measured= 125

CO (%)

idle: Max=1.00 measured= 9.99
2500 RPM Max=1.00 Measured= 1.80

Anyone have any idea as to what might cause such high readings? BTW, the engine runs great. Idles smooth, has no hesitation and has lots of power.

Thanks for your help.

It's running way too rich. Assuming you still have the original electronics present try testing the duty cycle as described in many threads here, also perhaps try adjusting the air/fuel mixture while doing this to see if the duty cycle reading can be brought close to spec. The catalytic converter can't do its job at this time since there is virtually no free oxygen present in the exhaust stream with the way the engine is currently running.

Emissions fail
 

Davestx,

I'm not too familiar with your model, but the oxygen sensor might be the culprit. I'm not sure if it would read quite that high, but still it's a place to start. What year car is this? early 80's cars that were sold in California had extra emissions stuff than cars sold in the other states, and were equipped with air pumps (also called smog pumps) that pumped air into the exhaust to thin it out. California cars also had EGR valves on the exhaust. In the early 90's, they started putting these things on all the cars. California has way higher emissions standards than NY does, and it seems like your car might be set up for NY rather California. Check into that.

Good luck

The car is a 91 and is a 50 state car. It has all of the emissions gear in place including a smog pump and EGR valve. I have decided to bring it in to my mechanic tomorrow and let him give me an estimate to get it into shape. Thanks for your replies.

I guess I should have read the bottom of your post, where it says the models and years of your cars!:rolleyes: Good luck anyways. Please post what the problem was, I am curious to know!

For sure the car is WAY too rich, have you tries adjusting the mixture so the O2 sensor can have control of the system...closed loop

Also don't forget the basic stuff like a new air filter...