[svxistentialist]

Originally Posted by Peter73

Hi,

I have a question about the sensors in the exhaust pipes. I have a EG33 engine from a 1991 JDM SVX. In the exhaust pipe are 2 sensors ( 1 left and 1 right), these are the "lambda" sensors or o2 sensors. 20 cm further there are another 2 sensors in a sort of small muffler left and right. What are these sensors and what are they for?

Thanks,

Peter

Peter, it is a little difficult to understand exactly what you mean by this question.

To the best of my knowledge, there are only 2 in total O2 or lambda sensors, one right and one left.

Now these two sensors are connected into the first catalytic convertor in each exhaust line. They might look like small mufflers, they are actually small cats.

The car has three catalytic convertors in the system. There is one each side in the exhaust pipe coming back from the "headers", the exhaust ports from each head. Farther back where the two pipes merge into one, there is a third catalytic convertor there as well.

The O2 sensors are plumbed into the two initial catalysers. This is where they take their readings from.

Where are you seeing two other sensors? I find this bit hard to understand.

Joe