My TPS was shot, as was the O2 sensor connection. As a result, I was running very rich for a while. I've since replaced the TPS, and fixed the O2 sensor connection. However, I suspect that the O2 sensor was fouled, and as a result, I'm still running slightly rich, and gas consumption is ~20mpg on the highway.

I looked around and it seems that a generic Bosch O2 sensor from DriveWire.com is ~$90!!! and the OE sensor is ~$140

So... does anyone know of a cheaper source for an O2 sensor?? Thanks!!

If you have the Bosch FI, then any 3-wire oxygen sensor will work. The cheapest I’ve been able to find is for a Ford 5.0 V8 – it should be about $40 at your local auto parts store for a Bosch sensor.
The $140 sensor for your car is EXACTLY the same sensor as the one for the Ford V8. The only difference is the connector. So cut your connector off, reuse it on your new sensor, and save $100. Not a bad deal, eh?

Jeff Pierce
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'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

The 96 and up 960 series uses a 4 wire O2 sensor system. Any source for those?

Sorry, no. Is that a Regina system?

Jeff Pierce
--
'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

It's a Bosch Motoronic 4.4 system.

If it's a Bosch system, then Bosch must have made the sensor. 1996 was the year everyone switched to OBD-II, right? That's probably the only difference. Try going to your local parts store, and ask to see a Bosch O2 sensor for a post-'96 Ford V8. My guess would be that it's a 4-wire sensor and that it would work for your car. (but that's just a guess -- I don't own any car made after '93)

Good luck, and post back with what you find out.

Jeff Pierce
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'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

sweet!! that's what I wanted to hear!! so the 5.0L ford V8 works... does anyone know the thread diameter/pitch on the O2 sensor? or do all O2 sensors have a common thread?

Thanks!

They're all the same. That same Ford 5.0 V8 sensor also works on my '92 Mercedes. (and all other cars with a 3 wire sensor)

Jeff Pierce
--
'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece -- sold to a loving home), '85 Jeep CJ-7 w/ Fisher plow

Just picked up a Bosch 3-wire for a 92 Mustang 5.0 for $42 at a parts store. Thanks for the great tip!!!

Please let us know how removing the old sensor goes. I have not been able to remove mine yet. I think I have to drop the down pipes out of the car.
Good luck

Yep, the O2 sensor is a PITA. You have to disconnect the cat at the rear, and you also need an O2 sensor socket (a regular box wrench won't get to it because it is recessed into the cat housing)

Anyhow, I was just being an idiot, and decided to undo the midpipe at the manifold as well, and ended up breaking the stud from the manifold for cyl 1-3...

any ideas on how to fix this other than getting a new manifold?? thanks

Wow so a socket worked? I tried both a regular O2 sensor socket and on offset socket. the Regualar socket was too long and to offset was too thick. I guess I will try again.

The stud broke? Hmmm. I don't think the stud is welded to the manafold but I could be wrong. How about put two nuts onto the remaining thread, lock them together and try to unscrew the stud out. Good luck. Im going to give the O2 Sensor another try. Let me know how it goes.
Justin
94 965

I got the O2 sensor on with a socket from Autozone. They actually have these sockets for rent!! You probably need to play around with a couple different sockets to get one that works. The autozone set came with three sockets, and only one had thin enough walls to work.

Also, for those who choooses to buy Ford V8 O2 sensors... I got one from a 92 Mustang GT for ~$42. The white wire that is adjacent to the black signal wire is the heater ground, and the other white wire, diagonal from the black signal wire is the heater power in. The pink wire on the Volvo is heater power in, and the black wire is heater ground. Green is signal. However, the mustang O2 sensor came with only about 6" or wire.

The studs are threaded in... I took the manifold out, and am now soaking it with penetrating fluid... I've got a tank of mapp gas and will try heating it up later, and see if I can get the stud out. There's not enough thread left for me to put a nut on.

Good luck with your O2 sensor replacement. I have to retract one thing I said earlier though... you DO NOT need to take the cat section of your exhaust off... in fact, with the right O2 sensor socket, you dont' even have to touch the exhaust pipes at all; there's enough clearance between the cat and the heatshield for you to get the socket and a 1/2" ratchet in there, no problems. I made this out to be a much bigger ordeal than required... DOH!!!

Dear NormL,

Good p.m. and may this find you well. It is sometimes possible to remove a broken stud, if you have a Dremel Tool. This is a small, hald-held motor, with a chuck (tool-holder) at one end.

For this tool, you can get a mandrel, onto which you mount an emery disc. This disc, about the diameter of a US 25-cent coin (1"/25.4mm), is hard enough to cut case-hardened (armor) steel.

If the broken stud sticks out from the surface, from which you want to remove it, use the emery disc to cut a slot from one side of the stud to the other. Widen the slot enough (by making a parallel cut right next to the first cut) so you can insert a screwdriver. You may be able to "turn out" to stud, even if there's not enough sticking out, to grip with a vise-grip pliers.

Even if the stud is broken-off flush with the surface, you can usually make a side-to-side cut. Simply avoid going too deep (how deep is "too deep" depends on the adjoining surface). 1/8" depth should suffice to give a screw-driver purchase.

A combination of penetrating oil (e.g., PB Blaster), gentle heat, and gentle tapping, and some torque (from the screwdriver) might "persuade" the stud stump to come loose.

If all else fails, take the part to a machine shop. They can drill out the stud stump, likely so precisely, that you'll not have to have the hole re-tapped.

Hope this helps.

Yours faithfully,

spook

Thanks Spook. I took the manifold to a welding shop, and they used a torch to heat it and remove the studs. I came home, and used two M8x1.25-1-1/2" bolts to install the downpipe to the manifold.

Wired up the O2 sensor, changed out the horribly fouled plugs (doh!!)... replaced the front brake rotors with Brembos from FCP Groton, bled them, reset the check engine light, and went for a drive

Smooth...

The power is back, the gas mileage is great, the engine revs smoothly and freely, and the brakes are firm and smooth.

All is well again. Thanks everyone!

No Bosch O2 sensor will work (properly) if your car has the Regina FI system. But I think there is now an aftermarket sensor option. Just make sure you find one specified for the Regina FI.
--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

I believe the 960 has Bosch FI, right? I remember checking this before, and somehow came to the conclusion that I have Bosch. Could someone confirm this?

Anyhow, the O2 sensor on the car right now looks just like the replacement OE Bosch sensor... if that means anything

http://www.buyoxygensensors.com/