<FONT face="Arial, Helvetica, sans-serif" size=4>Can anyone help I have an older lantra and I am having a problem reducing CO emmissions at fast idle 2300 rpm. Natural idle is ok at 0.45 Fast idle 0.51</FONT></P>


<FONT face=Arial size=4>Have changed Lambda sensor, plugs, ignition leads, and oil treatment to help compression. None of these changes made any difference whatsoever. Please advise.</FONT></P>


<FONT face=Arial size=4> <IMG style="CURSOR: pointer" onclick="AddSmileyIcon'smileys/smiley19.gif'" height=20 alt=Cry src=smileys/smiley19.gif width=15 border="0"> </FONT></P>

 

First off a high CO count indicates a rich a/f mixture.
Second- is the car fuel injected or carburated?
Their could be a bad vacuum linegoing to your fuel psi regulator, check all vacuum lines.
Catilytic converter might be bad also
fuel injector stuck open
pluged air filter
cylinder missing or dead
These are a few things to ponder
Tony

 

My first guess would be that the problem is exhaust related. If you had a dead piston you would notice as well as a stuck injector. I am willing to go with a bad catalytic converter, I hope you didn't remove it, that is usually a number one culprit.