Say I want to run open loop (locked fuel trims at any rate)...

1) I don't like the idea of wasting the gas from ridding the CCP. When would be a good time to purge, without running pig rich. What about dropping the idle VE and purge then. Give me your ideas. I'm expecting I'll need to change the program, just need to know what conditions would be good. Seems to me this might not work well since the canister could 'run dry'.

2) Haven't found an answer to this in searching, but will running open loop close to 14.7 be harmful to the cat, or is it imperative to switch high/lo, for the life of the cat. I have no emissions to pass, but I like the cat keeping the sound levels down and also feel better about keeping the air our children will breath clean, so I'd like to keep if I can.

Thanks,
Ben

 

I think the best time to purge is off idle accel/light throttle cruise. Couldn't you run into a hunting idle if all of a sudden you're dumping in a bunch of extra fuel, then none and so on.

I don't think that having a near stoich condition would hurt your cat at all. Cats work best near stoich, I think having the AFR swinging over and under stoich was just to get as close as possible with the algorithm they were working with.

Just an educated guess, maybe someone who knows for sure will chime in here.

 

That's why I'm asking More or less I'm asking if anyone has done it without fuel trims. Not looking for freebies, I can do the legwork, just want to know a good time or method of dumping the CC.

That's what I was thinking on the cat, it should go above/below normally when driving, but maybe not with the quick switching action that the integrator does.

 

I hear you on your concerns about the cat and glad that people are "enviromentally motivated". It is often stated that you need to "drop out" of Highway Mode periodically as HM runs at a constant lean ratio without any rich/lean cycling - unless you use that particular parameter. But, I used HM for over 3 years WITHOUT using "cycling on/off" parameter. And, I never had any problems with my cats and got fantastic gas mileage.

The only cycling "on/off" that would occur was when I would drop out of Highway Mode due to a steep hill or going into WOT. But, there were definitely periods of driving where I would be in HM extended periods exceeding a couple hours of steady "flat land" driving on a freeway at a constant 70 mph - with no cycling out of HM whatsoever. And, my cats were still operating properly as I had to due a couple of IM240 dyno tests. The results I got was consistent with prior years of emission testing.

I'm just mentioning this as "my own testing experience".