Reply
Terry!Being ASC certified & running a smog station for many years,So just for the sake of argument & discussion.Smog failure diagnostics most often involve a tedious process of elimination. The read out you get from the station is just like a trouble code, often won't exactly tell you what it is but will give you a point of reference & a path to follow. H.C failures are the most common.Caused by missfires,First check the obvious, all the ignition components,vacuum leaks,low coolant below 180 degrees,cam timing, The reason I'm not big on gas additives are the effects they have on converters plugs & 02 sensors,Octane boosters,racing fuels, etc. kill these items.High C.O. failures are the next.chances are what ever effected the H.C.readings also influence C.O. big injectors,jacked up fuel pressure,chip programming ,saturated fuel cannister,plugged air filter,weak chargeing system to mention a few.NOX is next, caused by high combustion chamber temps, timing, EGR valves, vacuum leaks, carbon deposits,to mention a few. I have just scratched the surface on all the things that can cause failures & a poor running vehicle to boot.Once all of this is verified & correct should it fail then get desperate & swap a chip with less timing,You call it a smog chip if you wish.I guess my point is that band aids can sometimes help but won't cure the problem. Regards LouTerry_H said:You're not a proponent of smog chips? Ign and inj timings won't help reduce emissions? My car was tagged a gross polluter before I began using a smog chip. Coincidence... maybe?