C.O. readings are a bit too high

[88canadianvette]

does anybody know what would cause high carbon monoxide readings in my 88"? either than a faulty egr valve im not sure what it would be.

 

[KOPBET]

Well, no one has jumped on this so I will give it a try. Firstly, let me say up front that I am not a mechanic or an expert. So if anyone wants to correct me, jump in here.

I don't believe an inoperative EGR valve would cause high CO. My understanding is that this condition would cause high oxides of nitrogen.

High CO will (I believe) result from anything that can cause an overly rich fuel mixture, such as a leaky injector, lazy O2 sensor, incorrect fuel pressure or fuel pressure regulator, resulting in incomplete combustion of fuel. Additionally, you didn't mention engine temperature in your post so I assume you meant high CO during normal operating temps. Had you meant high CO during warm up, an inoperative AIR, I believe, could cause this. Another cause of high CO could be the CATS. The CATS add oxygen to the exhaust to oxidize hydrocarbons into H2O and CO into CO2.

 

[Top]

Did you fail an emissions test? Did you pass the high rpm portion but fail the idle? In Vegas you can test your idle between 350 and 1250 rpm. I flunk at 600 but pass at 1100. I pass the high speed test no problem. Go figure.

 

[88canadianvette]

thanks for the info. i will look into your suggestions.