09 WRX O2 Sensor Type?

[crazyfast]

Hey yall.

Sorry if this is a noob question, but I could not find the answer to this anywhere. I am looking a lot in to the capabilities of the Cobb AP and reading through their Street Tuner how to guide and noticing that the suggest buying an aftermarket wideband O2 sensor to log and tune with.

I just kind of assumed that a car that is this new that comes factory turbo-charged almost has to come stock with a pretty good wideband O2.

Is this not the case?

[newtothegame]

You would need a gauge to see and monitor the A/F ratio. Im pretty sure thats what they are suggesting. EGT also helps some.

[ratfink]

Stock sensor is a narrow band.

[crazyfast]

really!? that is insane... how can the stock ecu keep the afr's in check then? oh well...

in that case, does any one have any experience with a wideband that is compatible with the AP so afr's can be logged?

[ratfink]

The ECU doesn't, it relies on parameters from the programing to relay fault info. This is precisely why a tune is required when known intake/exhaust parameters change.

I think there are several bosch sensor that will work, but I would ask the manufacturer of the meter your going to use to interpret the data what sensor they recommended.

[crazyfast]

wow. good to know that the ecu doesnt depend on the afr's. i haven't dealt with many stock turbocharged motors, so i always revert to the aftermarket stereotypes.

and i guess i'll make sure to contact cobb about a sensor before i order my ap.

thanks for the answers!

[ratfink]

Don't get me wrong, the ecu does use the tiny amount of data the stock o2s give it, but only in conjunction with the incoming air data. That is the reason tuning is often required when you change the intake. The ecu can't figure where all the air is coming from. LOL