I hear LS1 PCMs have whats called "lean cruise mode". Basically its where they can command a leaner(16.1:1) AFR while crusing on the highway to conserver fuel.

Why cant we do this with OBD1 or is there a way?

Also for those who know LS1 tuning software... can you set the desired AFR to leaner than 14.7:1? I thought I read that was possible.

 

LS1s have that? I know the TPI cars have it, but it was disabled from the factory. My TBI Caprice has it, and it was actually enabled from the factory. I didn't think LT1s had it. I figured the sequential EFI was good enough. They put it back in LS1s, but turned off?

 

They are turned off by code... no way to turn them on on US Cars.

 

Turned off or doesnt exhist?

I KNOW I read about LS1 PCMs having this ability!

 

the ls1 pcm is CODED OFF... the tables are there... you can change them.. but they are CODED OFF.

 

I wish I knew more about manipulating the PCM. Just very basic work with VB.net which I actually opened a .bin file up with... all it did was confuse me more.

 

If there was a Tunercat for LS1 cars, it would probably be there by now. I e-mail him all the time about adding features to definition files. For example, you could e-mail him and say "could you please add a switch for enabling lean cruise mode as well as the tables?" And he'd reply back with a new definition file attached. Brilliant customer service.