I checked my OBDII information using my laptop and Harrison R & D software; failed the closed loop test; The front O2 sensor shows the classic cyclic waveform between about .1 and 1 volt; the rear sensor is a flat line stuck at zero. I seem to remember someone indicated there was a fairly-priced Ford replacement for less money that would work in place of the OEM.

I also understand the sensor is recessed in it's mount and requires a thin wall socket to remove. God! Sometimes I hate Volvo for trying to force drivers into their over-priced shops, but that another story!

Has anyone found a good price on a replacement? Anyone got any tips on replacing the sensor?

I replaced both O2 sensors on my 1997 965. I struggled for a hour with my old O2 socket head. Finally went to the parts store in search of alternatives. The newer style is a thin walled "crowsfoot" O2 wrench - less than $10. AutoZone will loan you this tool for free.

I stuck a jack stand under the frame just in case a tire popped, but didn't bother lifting the car off the ground. No need to lower the exhaust. There are good instructions somewhere in the FAQ. You'll need a few zip wire ties to secure the wires along the tranny and up the fill tube.

Good Luck,

I have to agree with jbowers. I tried the Ford Mustang O2 sensor on my 240 wagon. I am seriously considering pulling it out and replacing it with an OEM from IPD or FCP Groton.

I am still having troubles with an unsteady idle at stop lights and think bad wiring in the O2 harness could well be the culprit. I crimped the wires together, then later opened it up and tried it again. With such low voltages it is very difficult to make a good connection.

I'm more of a mechanical than electrical type but have done some wiring. If there is a poor connection the computer is left searching for the signal which could result in it going through the full range, thus the fluctuating idle. A posting in the 240 forum recently discussed this. I think I'm experiencing it :(.

Mike
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1988 245, 245K mi, 5 speed

Quote from Macs245: "I am still having troubles with an unsteady idle at stop lights and think bad wiring in the O2 harness could well be the culprit."

Is your foot on the brake when you experience this unsteady idle. If so, the problem is likley your brake booster vacuum check valve.

Jeff Pierce

Hi, If you want less hassle and pay less $`s in the long run, buy the BEST one from Volvo fit it yourself and you will get the BEST performance. You will save $`s on less gas let alone perfect running. I know I have been their when my cat was changed.

Regards

I don't know if 960s use a Bosch sensor. If they do, then you can source one from a Ford Mustang V8... say early 90s. There's nothing special about this Ford sensor, it's just that they happen to cost about $40... versus 3 times that for a "Volvo/Bosch" sensor. (and it's the same sensor with a different connector on it)

Jeff Pierce

If you really want to make life easier, get the Volvo one from one of the sponser's.

This will have the correct length of wires and connector on it along with markings for where to attach the tie-wraps. Getting a cheaper unit means you will have to carefully solder and insulate the wires on the new sensor to the Volvo harness and connector. If you are not an experienced electronics solderer, you may be setting a trap for yourself as the signals require really good electrical connections. (No twisted and taped joints or wire nuts.)

On my '96, the sensor was not recessed but it is on the top of the converter leaving little room to get a deep socket on there which is what you really would want to do if you don't have one of those purpose built adapters for your 1/2" drive. The heat may have it stuck on there quite good. The new one won't require any special torquing. It shoud have a little anit-sieze on the threads so be careful to keep it off the end of the sensor. I recommend purchasing one of those O2 tools to save yourself a lot of grief.
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'96 965, 16' wheels, Michelin Pilot Sports, rear 18mm bar + Koni, 201 HP cams, 142K. Put 200K on '85 745 TD.

If you have trouble with access, you can loosen the clamp that connects the down pipes to the convertor, slip the clamp forward and seperate the two pipes. The convertor will then hang down a little and you will have better access.

DEWFPO
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1998 S90 077,400 and 1995 964 154,100