Well I finally broke down and burnt a chip disabling closed loop. I think it is the right direction to go. But my question is, does highway mode get disabled if you force closed loop? Today I noticed the ecm never went into highway mode, as seen by my LM1 and Autometer guage, which is hooked up to my stock NB sensor.

Since highway mode is sort of open loop, ie there is no learn control, shouldn't it work with open loop mode?

What I did for open loop was raise the closed loop enable temp real high, lock the min/max BLMs to 128, and set the min/max coolant for BLM update real high as well. Of course I reset the ecm also.

I have not datalogged with my scan tool yet, but did some with my LM1. I think my maf tables will need some adjustment!!

Another quickie ? about open loop. How does it affect spark advance? My neighbor mechanic says if you force open loop, you are taking all spark advance out. IE same as pulling the EST connector to set your timing. Thus you will run at fixed timing which is in the dist. I say hogwash. There are no parameters thay say you need closed loop in order to get your advance.

What you all think?

 

 

Thanks novass. Just what I wanted to hear. I am surprised none of the "experts" responded to my post.

So can you still get good fuel economy running open loop all the time? compared to closed loop and highway mode enabled? I imagine you can lean out the AFRs under light load.

 

why wouldnt you want closed loop Isnt that the whole point of reburning your chip (to stay in closed loop instead of open loop after modifications?)

 

Yup, to a point. Also check out Grumpy's final answers on openloop and fuel eco.

 

I have found that the car preforms WAY better in open loop for me. I tuned using a WB. CL kept trying to make the car run too lean no matter what I did.