Back when I was doing my na-t project I was using a fic and had a horrible time with it fighting me. (even with no 0'2's) can someone explain why it was fighting me? (technically speaking) I really want to understand this subject better, and what I dont understand is why can these gs430 guys run neo's with it fighting them like this?
Also my car is running with no 02's, and its running great, my other question is why when I start the car, and no matter how long I drive it it stays in open loop but if I turn the car off and back on while still at operating temp, (like a gas station stop) my obd2 scanner tells me im in closed loop?? with NO 02's?? anyone know what its doing? or how I could force it into open loop 24/7?
Also, when I installed my new CAI, (no 02's) and reset my ecu (batt off over 1 hour) the car ran like crap but then after like 15 min ran fine...I know that is normal, but I thought it was the 02's that made the adjustments...what is making the adjustments?
sorry its kinda deep...and long, but i know someone like jeff, or whoever probably knows the answer and I thank you all in advance
Thanks
-Preston

 

I would assume that since you don't have the O2 sensors, then the car HAS to be in open loop all the time. Or at least in a "safe mode" where the ecu runs the car accordingly to the amount of air from the mafs, the coolant temp sensor, rpm, throttle position....

I really recommend you put those O2 sensors back on. I'm pretty sure the car will run much better. Without them, the ecu is basically "guessing" how to run the car based on a look up table of values. (safe mode)

That's why I think the car was "fighting" you. And most likely why the car ran like crap after you reset the ecu; because when you reset it, it wasn't in the safe mode.

 

no...thats not really it, I know alot about open loop and closed loop, just not why exactly its doing what its doing right now, and its running better than it ever has with no 02's, and its not "guessing" the amount of fuel, its running off of a set base map

 

gs300 or 400? Just curious?

 

1998
gs300

 

well, when i boosted. i ran the s-afc2 and the i-manage, then switch to the fic and now i'm running f-con. all three set up i never had a problem boosting. and i had all o2 sensors hooked up...i guess i'm the only lucky one.

 

lol i guess so,
just to clear everything up, this is not a na-t question, or how to make a piggy back work question, its a why is/did this stuff happening? what is actually going on in the computer to make this happen? im more curious than anything, i dont have nor do I plan to have a piggyback anytime soon, i just want to know why.
Thanks

 

Here is a good article to read about closed vs. open loop from Toyota.

http://www.autoshop101.com/forms/h44.pdf

 

hey man, that is a good article. Ive known most of that stuff but it did help me understand fuel trims. So according to that article I should only have any kind of "fuel trim change" while in Closed loop correct? also according to that article, the ONLY way a car will be in closed loop is IF the 02's are working. So why does my little obd-2 scanner say it is in closed loop (with all 02's unplugged) after the car has been at temp, shut off and turned back on while at temp? Is it a fault in the ECM? or the obd2??
Thanks

 

does it stay as closed loop, or does it go away after a while?

 

it stays in closed loop until the car gets turned back off, cools down and then back on, and then stays in open loop until turned back off and on again while hot (and i mean like if it drops to say 165-170 as opposed to 180 it will be in open loop)...I'm going to program my obd2 to read fuel trims this weekend, and depending on what that tells me I should be able to figure out whats going on.