99 Yukon 5.7
Old girl failed colo's emission test yesterday, twice.
Failed due to high NOx-gpm. After First fail I changed out the egr valve (internet info pointed at that) Second test still a fail but it did have a lower NOx-gpm figure, just not enough to pass.
My code readers generic, just shows the codes once you have an engine light on.
Trucks got 169k miles, replaced plugs wires and cap last year, ac delco parts. She runs good and does ok mileage wise.
So any good ideas as to where to start looking for my problem? Internets kind of a bust, could be 20 different things or 10 different sensors. Not wanting to throw a heck of a lot of $$$ at it buying parts till it passes! Or spend a week trying to figure it out.
Anyone have a good scanner that can pin point the problem?? Denver Co area.
Or any good ideas as to what to look for?
Old girl failed colo's emission test yesterday, twice.
Failed due to high NOx-gpm. After First fail I changed out the egr valve (internet info pointed at that) Second test still a fail but it did have a lower NOx-gpm figure, just not enough to pass.
My code readers generic, just shows the codes once you have an engine light on.
Trucks got 169k miles, replaced plugs wires and cap last year, ac delco parts. She runs good and does ok mileage wise.
So any good ideas as to where to start looking for my problem? Internets kind of a bust, could be 20 different things or 10 different sensors. Not wanting to throw a heck of a lot of $$$ at it buying parts till it passes! Or spend a week trying to figure it out.
Anyone have a good scanner that can pin point the problem?? Denver Co area.
Or any good ideas as to what to look for?