O2 Sensor(s)

[pacman67]

For background, Bought the 98 T4 with no exhaust system, everything after the turbo was removed, and owner gave me one sensor which was apparantly the only one on the car??
I obtained a used exhaust system from a later car, which did not come with the downpipe/elbow, which i later obtained from a local volvo specialist, who removed from a t4 engine.
So i have one sensor which with kind advise from T4rick and Clan, appears to suggest that the car should have two, although a Vadis search with vin number suggested only one. If i fit the sensor (4 pin plug) i have in the rear position it wont reach the socket on the bulkhead.
Has any 98 t4 owner looked at the o2 arrangement, (are there more than one) and can advise.
My t4 is 99 plate but i believe to be a 98 build.
Thanks guys, as this is driving me round the bend.
I will try and get some pics up later.

[Darlo 1]

Have got a 98 T4 sat on my drive, will have a look tomorrow night and post up.

[andy_d]

from what i recall, mikeyskona had a 98 T4, he deffinatly had 2 o2 sensors,,

the front lambda does indeed go up into the engine bay at the back of the engine by the Fuse box on the rail. The Post Cat lambda however goes inside the car

so there Should be 2 and a 2nd place in the car to plug into,,but dont ask me where

[Baffler]

As said, there are two sensors. The front one, on the downpipe, connects onto the series of connections on the firewall. The rear is fed through the exhaust tunnel, underside of the car, and connects into its male connection inside the centre console.

Have a peep at these threads:

http://www.volvoforums.org.uk/showth...+lambda+sensor (Note: the location/route of the rear sensor on VADIS is incorrect)

http://www.volvoforums.org.uk/showth...+lambda+sensor (post #88 for pics)

[960kg]

.....when replacing the rear O2 sensor before you pull through the wire with the small plug on from under the car tie a piece of long string on the plug end inside the console then when pulled through swop the new for old on the string then go back inside the car and pull it back through the hole in the floor and passed the wires inside the console......if you don`t do this you can`t get your hand near the hole inside properly to pull it through as the space is so small, also depending how big your head is it is difficult to get it under the dash to see where the hole is inside the console!!!!.......Hope this helps?...

[pacman67]

Big thank you to one and all. I did some investigating this eve, and following all your info, i undid the main heatshield, and a lambda probe dropped down.
Total result. Ive plugged in the front one, and have sourced a boss to weld onto my front pipe. Thanks again.

[Darlo 1]

Yep two o2 sensors.

[pacman67]

Could anyone give me a rough measurement of the boss position for the front probe. Just a down distance from the flexi on the downpipe, then i can get one fitted.

[T4Rick]

Just bottom of downpipe on the bend before it goes under the car.I sent you a pic of it

[pacman67]

Originally Posted by T4 Rick

Just bottom of downpipe on the bend before it goes under the car.I sent you a pic of it

Yes thanks Rick, wasnt quite sure if it was on the bend or just above, but youve answered it now. Thanks again.