What is this?

[mattgold]

OK so I am wondering whether this is an oxygen sensor, I am suspecting that my current hesitation problems could be due to a broken sensor. From what I have read modern subes have two o2 sensors, one before the cat and one after. (Mine is a '99 ej20tt RHD) This is a picture from under left side of the exhaust manifold - is this the one after the cat? (I have found the sensor is always slightly loose when I am under there changing the oil and I try to crank it tight with an open crescent, but the heat shield makes that very difficult)

 

 

Searches here indicate that the first o2 sensor is located on the RHS under the air intake ?

 

(I believe the current o2 sensor was replaced >80k kms ago, so probably is due for replacement anyway???)

 

Matt.

[porcupine73]

Hm...not really sure from that pic, but the real way to know is to locate both o2 sensors. Not sure about your specific model, but in general on n/a models the rear o2 sensor is sort of under the middle of the car. The front o2 sensor is generally on the right side sort of near the front diff.

 

Not sure about suby's but some makes have two front o2 sensors and two rear o2 sensors they probably have dual exhaust.

[wtdash]

If it's right after the exhaust manifold, it's in front of the Cat. ...I've changed the front one by reaching down between the engine and firewall, and it's closer to the passenger side - on the US model. The other one is just behind the Cat on US models...about equal w/the driver's door.

 

Can you get a wrench UNDER the heat shield or remove it? Otherwise, you'll need a O2 socket w/a cutout for the wire like these:

http://www.autozone.com/in_our_stores/loan_a_tool/exhaust/oxygen_sensor_wrench_set.htm

 

 

Good luck

[mattgold]

If it's right after the exhaust manifold, it's in front of the Cat. ...I've changed the front one by reaching down between the engine and firewall, and it's closer to the passenger side - on the US model. The other one is just behind the Cat on US models...about equal w/the driver's door.

 

I think it is in front of the cat, because it would be alongside the front left wheel... You can't see it in the photo above but I have another that shows when looking up at the sensor the windscreen washer bottle is in the background (ie almost directly above) - the wiring from the sensor actually runs back towards the front of the car, joining into a wire bundle near the battery iirc.

Here are a couple more pictures from underneath, not sure if the cat is part of anything there or not - hey maybe it even has two cats???

 

See the heat shield on the rhs of the first pic (ie lhs of car), that is where the sensor is iirc. Presumably that is in the exhaust manifold before the turbos (so it would have to be before the cat then ....)

 

 

M.