[enkeivette]

Lars Grimsrud claims that ANY car can be tuned to pass smog. I'm sure that is with the exception of cars burning oil and/ or coolant. But any... car that's running right? Bold claim, but I'd never be one to object to something that he said.

[Vettezuki]

Originally Posted by enkeivette

Lars Grimsrud claims that ANY car can be tuned to pass smog. . . .

Yeah, that doesn't make any sense to me at all.

[big2bird]

The main trick is to lean it up and retard the timing.

[geeeezer]

A too lean mix will blow the HC reading off the scale and ultimately kill the catalytic converter .

G

[Vettezuki]

Originally Posted by geeeezer

A too lean mix will blow the HC reading off the scale and ultimately kill the catalytic converter .

G

I thought it was the other way. Lean means hotter, more NOX less HC. Rich means cooler, less NOX more HC. In other words you can't really go too far either way before getting bounced by the sniffer I suspect.

[geeeezer]

You are quite right about the nox , but a lean mix will result in a lean misfire and swing the hc reading up and drop the co's . Enrichening the circuit will bring them down but also will cause a co rise . In the end it is a balancing act and varies from engine to engine . The egr sys is utilized to drop egt and lower nox .

G

[Vettezuki]

Thanks for the xtra info. I know lean misfires can fry O2 sensors very quickly. My LS engine is setup as a 2001 Camaro, which I believe is the first year there were no EGR.