Quote:
Originally Posted by beetle1303
Mike, as u said it is confusing...
but how could an EGT sensor be used for emissions? im not saying that it can be used for performance either. not directly at least...maybe as a safety cut off to go into safe mode??if EGTs run really high?
From general theory, performance is affected by emissions and vice versa. The way to monitor that is through an O2 sensor often called lamda (λ=1=14.7 ideal mixture) and in an efi system the ecu is able to sense and alter fuel delivery and/or ignition timing...
another thing to consider is: was this engine propelling only one car or was used in other applications as well? sometimes in order to minimise production costs, they use the same parts through the whole range, or upgraded versions of the same engine are defined by simple to them changes but very confusing to us that we dont have all the application info about the product. just a thought
Chris
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EGT is directly related to emissions, the temperature of the exhaust is a direct correlation between if the engine is producing nitrogen oxides or sulphur oxides (I think its sulphur). Searching the nasioc.com site revealed that the EGT will only send a emission light on the cluster if exhaust temps go out of range, the ecu won't alter timing/air/fuel based on its reading, only the 02 sensor.
Emissions is tied to performance in a way, except it depends which kind of emissions you want to get rid of. When combustion temps are high (running close to ideal air/fuel) = lots of power, I think its the NOx that is produced, and when temps are low, I think its the SOx that is produced. As far as I know, the idea for emissions is to keep temps low so no NOx are produced and then reburn everything in the cat. These low temps mean a rich air/fuel mixture, meaning not the most power. (I'm definately on a tangent, and I've haven't taken a course on this in a while so the details might be slightly not correct)
Talking to other people with this engine they have the EGT sensor as well. From what I can guess, the wiring for the EGT must go through the gauge cluster first before going to the ecu, and I don't have the cluster. Either way its getting the cut.