BitBasher

Your six conductor O2 sensor is a "wideband" sensor, as opposed to the common switching type 3 or 4 wire sensors. The wideband sensor must be replaced with an OEM unit, since each wideband sensor has a unique calibration resistor located in the connector. This link http://www.wbo2.com/lsu/default.htm gives a good explanation of its operation.

Recently I've noticed that the dash lights for the heater controls on my '01 Forester do not immediately light up when the headlights are turned on. This seems to be related to cold temperatures, as they will gradually come on as the interior of the car warms up... like in 20 minutes or so. Seems like it's related to solid state control... Has anybody else experienced this? Cheers

Had the same problem with my '01 Forester. Turned out to be a bad wheel bearing.

Thanks mtsmith, I'll be on the lookout for an MAP sensor.

I have a similar hestitation problem on my '01 mt Forester. No problems with rough accel or decel though. Replaced the front O2 sensor (OEM) - no noticeable difference. I did tweak the TPS slightly (can't remember which way) and that did help a bit. I had a look at the TPS resistance with an ohmmeter and it seemed to have perfectly smooth action, but perhaps it's acting up. Anybody had to replace a TPS prematurely?

We've had a 2001 Forester 5spd for a little over a year now. I wasn't pleased with shifting, being notchy and stiff, with a weak 1st gear syncro. With 80K km on it, I thought that it wouldn't hurt to change to synthetic trans oil. I couldn't find a GL4 oil locally, so I went ahead and used in Castrol Syntec GL5 75W/90. Shifting was improved, but the syncro on 1st was no better. After living with it for 30K km, I added a bottle of GM LSD (limited slip differential) friction modifier. Since then I've put 1K on it, and am happy to report a significant improvement.

OK... I've got some more info on this. It's a Wideband O2 sensor, Bosch LSU4. Generically known as a 5 wire pump cell sensor. (the 6th wire stubs at a calibration resistor in the connector. 5 wires go to the sensor). Details are here http://wbo2.com/lsu/default.htm. It ..appears.. that the sensor used on VW Jettas and Golfs, VW p/n 021-906-262-B. may be a suitable replacement, at half the cost of the Sub. OEM unit. (available at http://www.worldimpex.com/item_detail.html?sku=117395 ) I'll have to dig in to it a little further.

Hello All. I know that this topic has been pretty well hashed out over the years... well I guess it's not over yet!. Anyway, my Forester seems to be running richer than it should and I suspect a lazy O2 sensor. No trouble codes show up, and no, I haven't done ay diagnostic tests. Trouble is, the front sensor on this one is a bit of an odd ball with a 6 lead cable. Can anyone shed some light on the workings of this sensor. The OEM unit is a little pricey, so I'd like to replace it with a universal sensor, but that doesn't seem possible. Any ideas?