Oxygen Sensor Help

[Ceddy]

Just bought a Talon and I'm trying to get it ready for Inspection/Emissions.

Having problems with the front oxygen sensor, and the more I figure out the more questions I have.

Any help would greatly appreciated. I only have to the end of the month to add all the emissions stuff, everything was removed for racing.


Heres my set up: 95 Talon TSI AWD with 6-bolt motor and 14b turbo. SAFC II installed.

I've been getting CEL for Oxygen Sensor Heater.

And I put in a A/F guage and it reads lean all the time. (I know A/F guages aren't good for tuning, but its been very helpful troubleshooting the oxygen sensor)

When I was installing the A/F guage I spliced to the ECU oxygen sensor wire and saw the SAFC II already had a wire there. I thought the SAFC only changed air readings. When I unhooked this wire I got VERY high knock readings.

So I got a Bosch sensor today(Part# 15704). It has a different harness. Can I splice this to the old harness? If so what wire to which? The Bosch has 2 white, a gray, and a black.

Also are the sensors the same between 1st and 2nd gen? I don't know which down tube I have. The sensor I have in looks a little smaller. But that might just be me.

Is there easy way to remove it? I can't a wrench in there at any angle.


Thank you very much.

 

[kenamond]

Is there easy way to remove it? I can't a wrench in there at any angle.

Get an O2 sensor socket. It's a deep-well socket with a slot cut out of the side for the wire to go out. I forget if you have to remove the lower heat shield or not. The heat sheild is a bit of a pain to get out, but just taking the bolts off of it may be enough - and you might not even need to take it off. Either borrow or buy the socket and some antiseize compound and go from there. Sorry, can't help with the rest. Good luck!

 

[Old Mitsu Tech]

I would scan your computer for codes. I would also look at the data stream on the o2 sensor. If it has stalled and not moving, depending on if it's lean or rich, I would spray some propane in the intake and see if it moves if it has stalled lean. If it has stalled rich, you can pull a vacuum line while observing the data stream. If it goes lean, it's likely the o2 sensor is ok. .450 volts is the median range on o2's if they are one volt setups. If it's lazy and just refuses to move, then it's probably a bad o2 sensor.

Good Luck

 

[Smokin80]

I just diagnosed a bad oxygen sensor today at work....usually they will just read some random voltage like say .29 the entire time and not change if it is bad. but if its just giving you a heater code than maybe just check to see that the heater wire going to your o2 sensor has power. ... if not ## goin to have to check your wiring harness...if yes...its most likely your o2 sensor that is gone. not an overly expensive replacement but i would say just spend the money and get an aem wideband with a analog out and be done with it. It will give you excellent tuning abilities should you go that route and will still give your ecu an analog signal to work with.

PS the stock front o2 should read lean rich lean rich lean rich lean rich all the time when it is idleing or there is def a problem

 

[Generation X]

I think I have a bad upstream 02 sensor because it is not doing nothing at all. Even my S-AFC says 0.00 and my logger the same.

But.... the question that I have is what other issues, and or problems do you guys think that a bad 02 sensor will cause other than poor gas mileage?

Will it cause our cars to go into limp mode for safety, or can you just keep tuning and just get bad gas mileage only?

Reason being is I just installed an FP Green and I'm trying to work out some issues, and the 02 sensor seems to be one of those issues.

Thanks for any input!