Originally Posted by KEVIN KIRELUK
High NO #'s are generally caused by a lean fuel mixture.


Yup. Leaner burn is also a hotter burn. Nitrogen and oxygen in the air combine to form NOx under these extreme temps. I think the temp is around 2500degF. Either way, our motors combat this high NOx by recirculating exhaust gases into the intake tract via the EGR valve.

Chance are the EGR is broken or the vacuum lines going to it are not correctly working or hooked up.

11.254@132.14MPH - Tractionally impaired