Remove Primary o2 Sensor - Always Open Loop???????
 

My buddy has an 04' Civic and he used the Apexi Neo. He got it tuned at Innovative (Buffalo NY) who tunes supras etc. (very reputable company). They disconnected his primary o2 sensor to get the tune to stay. I am assuming this is due to the same closed/open loop situation as the tC.

1. If I disconnect the primary o2 sensor, will the ECU always be in open loop just using the MAF to adjust fuel/timing? Allowing me to use the Neo to its full potential?

not familiar about the neo but disconnecting it will make it stay in open loop.. if you decide it to run it like that, just make sure that your tune is dead on, that way your car wont be drinking gas or running too lean

That is interesting. I thought that if your o2 sensor is bad or missing the car will go into a safety mode?

Thanks for the quick response! I was hoping that would be the case. His ran awesome - In the case, I might as well have them tune it and save my a$$ in case I dont tune it right - ANYONE ELSES "o2 CENTS" WOULD BE APPRECIATED!

it should go into limp mode if u do that.

that is true, but he is running another engine management that takes over so it should be good.. i personally havent tried it but it has been discussed previously..

so that means you still have to setup the engine management to give the ecu the "its all ok" signals for the 02 sensor correct?

I dont care if it throws a CEL - As long as it runs safely. I can disconnect the Apexi Neo for inspection.

Sorry for the repeated questions instead of giving answers, but we can all learn something lol. Again I thought if you are throwing a cell, it will put the ecu into a limp mode... So if you take out the 02 sensor you will have to have something that will trick the ecu into thinking its still there..... thats how i understand it .

Im running 6psi right now with stock injectors/stock tune/stock everything and have been running problem free for over a year(beside oil leak-custom kit) I am running 2.5" intercooler piping and FMIC- I have no CATS and have a CEL from that??? Do you think it is running in limp mode right now? hmmm hopefully some one knows.

not sure that is beyond my tc knowledge, hopefully paul or someone will chime in.

On a stock tc with certain sensors that are bad it goes to limp mode and may dump fuel and retards ignition to protect the engine.. try disconnecting the maf or O2 sensor and you might notice pig rich afrs, but when there is another source of signal like a piggyback that controlls ignition and fuel then that limp mode goes away because the ems tune takes over.

he says he has a neo afc though, can it do all that?

i unhooked mine for a few days awaiting my new sensor to come in from ebay and omg it sucks lol running 11-12 afr all the time lol and pulling crazy timing - dont do it - get a fic that can spoof the 02 sensor :) O yea as for y i pulled mine - it read lean so the car would try to overcompensate and die lol so i ahd to run without it while awaiting my new one :P

Yes, your in limp mode. ____ for fuel economy and power.

What?? You shouldnt be in limp mode without cats.... Thats the only thing from that quote it appears u dont have - i dont have my secondary 02 sensor and mines not in limp mode - just a second 02 sensor failure unless i missed something, like missing something else

talk to garage1217. what happens is, you disconnect the primary o2 sensor, and the car goes into limp mode, and runs very rich, but you simply tune the limp mode fuel map, and the car won't know any better, and since it doesn't have feedback from the primary o2 sensor, it doesn't relearn. but garage1217 did this with emanage ultimate.

I ran mine turboed the whole time witout a primary o2 sensor. I was on AEM F/IC

when i ran mine without it pulled alot of timing according to the scanner i was using - anywhere between 10-20* based on rpm during acceleration - how did you compensate for this - no piggyback i know of can advance ign timing

Iunno.. I just had the f/ic it ran good tho so i dont know..