chip plus oxygen sensor advice

[shayden69]

Gday, So ive got a greenfoam tune on the way 4 my 89 VN. buh hear me out.

I have a massive custom built cold air intake with a K&n pod that takes in loads of air, and if im getting a greenfoam chip which kinda works by throwing more fuel through my engine..

more air combusting with more fuel, will my computer know how to mix these right with out an oxygen sensor?? oxygen sensors work by telling the computer how much unburnt fuel etc is going through the exhaust..

just a theory, need your opinion

chuur

[Not_An_Abba_Fan]

It doesn't matter how big your intake is, the engine can only use as much air as it can use. It doesn't really matter whether you have a 20" pod or a 5" pod, (I hate using this term but it is the easiest to understand) the engine can only suck in so much air.

The tune changes the injector duration and the ignition timing to make it better for the engine, the ECU will also use the O2 sensor signal to trim the fuel as it needs to. The O2 sensor doesn't measure unburnt fuel, it measures the amount of oxygen present telling the ECU whether or not to put in more or less fuel to burn it more efficiently.

So you don't have an O2 sensor? As long as it's function is turned off in the tune, it won't throw an error code and make the engine light come on. It doesn't "need" the O2 sensor to run, just to try and get as close as possible to complete combustion and that magic 14.7:1 air fuel ratio.

[shayden69]

sooo would i be loosing any performance by not having a oxygen sensor?

And ive got 1 just havent installed it yet, only asking coz ive got a race lined up with a good mate whos got a ford version of my car. same year, both manual etc. will be interesting.

[Not_An_Abba_Fan]

O2 sensors are only to achieve emissions standards and to keep catalytic converters at optimum temperature so they work at their maximum. I believe NZ doesn't have the same emissions standards as here, so no, you don't need one. As I said, as long as the tune is for no sensor, it will be fine. My opinion is that they actually decrease performance.

[Circlotron]

One of our cars is a '92 Camry that does have a cat but does =not= have a factory-fitted oxygen sensor. I mean, it is not missing; they never fitted them to those models. Can't imagine the cat working as good as a system that does have the sensor but it seems okay. That said, if you go too rich for too long you are going to melt the cat off the pipe almost.