Oxygen sensor

Hello all,

I've recently bought a '98 900S turbo & was having a look at the fuses by the passenger door (like you do) & have discovered that fuse 38 for the oxygen sensor has blown it fuse. First off, what does the sensor do & is it the same thing as the lambda sensor? Second thing, is this likely to cause any damage if it's not working?

It runs really wells at the moment & I've not noticed any drop in performance, so I'm at a loss at what the problem really is.

tia

kds

Reply to
kingdoodlesquat
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First off, yes the O2 senosr is the same as a "lambda" sensor. The only part of the sensor that gets power is the heater. The purpose of the heater is to get the sensor up at operating temperature faster so that the ECU can go into closed loop mode faster. This design minimizes the higher emmissions period of "open-loop" warm-up mode. If there is a problem with it you would notice it about 3-5 minutes after a cold start when the ECU tries to switch over to closed loop.

Normally, you would then get a check engine fault of some sort. You may want to verify that you Check Engine lamp is OK, and has not been defeated by the prior owner or unscrupulous salesman.

Reply to
Fred W

Cheers Fred. Looks like I'll be forking out for a new sensor then - unless I can blame it on the crap fuel at Tesco's.

Reply to
kingdoodlesquat

I assume that you already tried changuing the fuse and it blew again? If so, you may want to just check that the short is not elsewhere in the wiring. If you follow the cable back from the O2 sensor you will come to a connector. Try unplugging it, then plug in a new fuse and see if the fuse blows again. If it does the problem is (obviously) not in the sensor.

While a shorted heater is not impossible, it's not a common failure mode for the sensors. That and they are pretty dear at ~$100 a pop.

Reply to
Fred W

I'm in the UK & its night-time at the moment, so I cann't get hold of any fuses just yet. Nevertheless, I look forward to frustrating myself tomorrow. Cars - nothing but a black hole in which to pour copious amounts of cash, but at least my black hole is a Saab!!!

Reply to
kingdoodlesquat

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