I'm posting this here because I haven't gotten a single reply from the prelude forum, and I've been asking there for a few days.

O2 sensors control air/fuel ratio. This is why you would get bad gas mileage when an O2 sensor is bad, right?

VAFC controls air/fuel ratio, right? Does VAFC replace the need for O2 sensors? Does it work together with the O2 sensor?

My MIL has been on for a few days with the "O2 sensor slow response" code. I haven't noticed any changes in performance, such as gas mileage. I was wondering how important it is to get this fixed.

 

vafc just a piggyback cheater they will have problems, and depending on the # of o2 sensors you have depends on what the pcm will read

 

There are two O2 sensors (primary and secondary). The CEL is "primary O2 sensor slow response".

The reason why I'm asking if this needs to be looked at is that, with the VAFC, according to NTPOG "Knowing that the OBD2 ECU will eventually learn and "detune" what you are working to achieve, the real objective here is to insure that your computer doesn't learn, or more accurately, "forgets" what it learns." Basically they suggest cutting the power to the ECU backup memory.

Also, the CEL that I'm getting only registers after two consecutive trips are made, so it would follow that if the ECU memory was wiped after every run, it woudn't be possible to ever get this CEL.

So, my reasoning is that I don't have to worry about this CEL, because anyone who has followd the instructions from NTPOG would never get this CEL, so I should reset the ECU and pretend nothing ever happened, as I had installed a switch for the ECU memory in the first place.

Good reasoning? Bad reasoning? Replace o2 sensor? opinions?

 

well, after a lot more searching, I finally found out that this OBDII work-around thing is bogus. So, forgetting about that, my remaining question is: Is "primary O2 sensor slow response" a big deal? Can the slow response be caused by having VAFC installed?