Quote:
Originally Posted by Stl-986
So, let's talk about exhaust & O2 sensors. Are there 4 or 6 on a 2000? I thought there were just 2, at the cat on the header. These are the 2 (red) that I have replaced. Is the 3rd (blue) really there and if so, what is it's purpose? Looks like it is on the secondary cat. And if there are 3, how come only 2 show up in any tester?
Assuming for a moment there is clogged cat. Would it most likely be the one at the header or the secondary cat? Waiting for pb blaster to soak in to get the front o2 removed on the header so my mind is just starting to think 10 steps further down the list. |
There should be 4 on stock dual exhaust systems.
1 O2sensor before each precat:
In simple terms they see unused oxygen from the combustion cycle which creates a small voltage.. The DME/ECU uses that voltage signal to adjust fuel trims.
Then you have 1 O2 sensor each side that are post cat.
They are for reading oxygen after the catalytic process. The DME/ECU compares the Pre and Post cat signals to see if the Cats are operating correctly.
So you have 4 O2 sensors total
No way of telling which cat could be restricted
If one is
Hybrid Mode
