webdawg

The clamp was completely loose.

Anyways.

Lets say I replace both sensors and it does not fix it. Will they be at any risk of being destroyed before I can get a new converter in it?

ruley73

As I said before, all of your oxygen sensors are identical parts. Knowing this, rather than install a new sensor, I would just swap the two downstream O2 sensors around, clear all the codes, and drive until the CEL comes on again. If you then get a P0430 code, this tells you the O2 sensor you moved to the bank 2 side (front of vehicle/radiator side) is bad. If the P0420 code comes back then it is probably a bad catalytic converter.

To answer your question, the O2 sensors would not be damaged at all. To add to this, you only need to replace the one O2 sensor that is bad. It won't hurt to replace them all, but it is unnecessary.

Again, I would be very surprised if your catalytic converter is bad. You want to be certain it is in fact bad because it will cost you over $500 in parts alone to replace. For comparison, one replacement sensor is only about $55 (AC Delco p/n 2134553 shipped from RockAuto). The only brands of O2 sensors I use are NTK, Denso, or AC Delco. I'm pretty sure your Equinox came with Denso sensors from the factory. The AC Delco replacements will probably be Denso parts in an AC Delco package.

Although AC Delco is the brand of most OEM GM parts, many AC Delco parts are manufactured/supplied by different companies and just have the AC Delco brand on the package.

webdawg

Can someone tell me what the 3rd 'converter' after the y pipe is on my vehicle? Is it just a resonator. The guys at GM parts had no idea and did not want to do the work to tell me. It was called a converter in the parts manual.

ruley73

It is exactly that, a third catalytic converter. It is item 6 in this diagram. Having the exhaust go through two catalytic converters is common practice on many newer vehicles.

webdawg

Why would it be unmonitored?

ruley73

I don't know the answer to this, but it is common for them to be unmonitored.

webdawg

Can someone tell me which converter is bank 1 and which is bank two?

ruley73

You should know this by now.

The "bank" refers to the bank of cylinders being identified. Bank 1 is always the bank containing cylinder #1 in the firing order. In your case, Bank 1 is the rear/firewall side cylinder head. Obviously, Bank 2 is the opposite bank; in your case the front/radiator side.

webdawg

So:

Front Bank= 2-4-6 (near radiator)
Rear Bank= 1-3-5 (near firewall)

Do you know what to search for in the OEM service manual to get a diagram of the cylinder numbers?

ruley73

The info you provided is correct. The service manual doesn't have a diagram. It just provides a description under the topic "Engine Component Description (LF1 or LFW)":
I was able to find a diagram from another reliable source (Wells Search Parts Catalog).