Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Emissions HELP
Thread: Emissions HELP
View Single Post
  #12 (permalink)  
Old 10-11-2003, 10:03 AM
dmorris1200's Avatar
dmorris1200 dmorris1200 is offline
doesn't play well with others
 
Last photo:
Join Date: Feb 2002
Location: Maine
Age: 48
Posts: 1,834
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Actually if you think about it, the EGR's job is to richen the mixture. That's why when it isn't working the engine runs too lean, usually pings, and fails for NOX due to increased cumbustion temps. What's interesting about his failure is that a failed CO could often mean different things in different applications. Any poor combustion could raise CO's (incomplete burn of fuel mixture) but his high NOX also tells a story of a lean mixture causing high combustion temps. Were his readings at idle, at elevated rpms? High combustion temps caused by excessively lean mixtures due to a faulty EGR could also cause poor combustion events causing CO's to increase. There are a lot of variables to this kind of stuff, it's not always as simple as 2+2=4. I agreed with the possibility of a faulty EGR as a possible cause but not because it causes a rich condtion. Rich conditions lower NOX readings.

PS. I don't think anyone said to un-hook vacuum advance, and yes if he is in a state that requires openning the hood like during an IM240 test he must leave pcv in the valve cover.


Last edited by dmorris1200; 10-11-2003 at 01:22 PM.
Reply With Quote