Getting a tune, should I have them delete the o2 sensors from the ECU? Heard this can make you run rich, but I'm getting a tune so does that matter?

 

If tuned correctly, then yes you can "delete" the O2 sensor inputs (ie: run continuous open loop)

 

What would be the benefits, if any? Besides not having a CEL when they go bad.

 

It will prevent the ECU from making fuel trim adjustments based on O2 inputs.

 

The car will only run rich if the car is not properly tuned in open loop (o2 sensor feedback disabled).

 

Okay. So it shouldn't be difficult for a decent tuner to tune it properly in open loop? Also, I have a VAFC installed into my harness, I feel like with a legit tune that having one is kind of redundant. Any advantages of keeping it?

 

Remove the vafc, sell it.
Talk to your tuner on his preference on open loop/closed loop.

 

Here is the problem.

Lets say you tune the car in open loop it runs great that day and its 80 degrees outside low humidity.

in 5 months its 25 degrees outside and dry your engine can't compensate for the slight changes unless you have the compensation adjustments dead on. An 02 sensor doesn't go bad "THAT" often I would honestly keep the 02 sensor even for a race car, you don't really gain much eliminating that feature.


Granted you can physically hear a difference between an engine idling in closed and open loop, something kinda neat.

you tune in open loop and then enable closed loop and go to town.

On the flip side of things closed loop is generally only used for cruise where your pulling less then xyz map value during cruise and idle. You can get away with it and people do but what's the point.


my 3 cents.

--Aaron

 

Doesn't your MAP and IAT sensor work with each other to get the right air density and therefore it will give you the right amount of fuel regardless of humidity and temperature?

 

There isn't anything in tuning land that will change fuel trims based off the humidity.

You can adjust IAT temp vs fuel or IAT vs Ignition correction trims. I know Neptune RTP has default values. These values would be very important if your tuning for maximum TQ output at every rpm value. You want more hp then stock but not to the point where your knocking on days when you have an extra passenger in your car or 15 degree hotter temps outside "That's way to aggressive of a tune"

 

idle in closed loop? hmm..

 

Just throw a wideband in the car, and delete the o2 sensors. I have that on my car, and it gets driven on the street all the time and to the track. I ran it disabled even when I didn't have a wideband in the car. Pretty much you won't have any issues disabling them with engine mgt. I would just reccommend getting a wideband, and if you can tie it in with your engine mngt. and it will make self corrections... etc

 

There is if your EMS supports a fuel trim from a 0-5V input.

It wouldn't really be worth it though.