webdawg

I have been to the dealer and they have told me that I need to replace 25800888. CONVERTER | Genuine GM | 25800888

Anyone have the procedure for this?

I am looking for procedure, torque, and what gaskets I would need.

ruley73

I'd think this would be covered by the 8 year/80,000 mile emissions component warranty. Since you're asking I'm betting that (unfortunately ) your Equinox has more than 80,000 miles on it. I was able to determine the part number you provided was for the back (right, firewall side) catalytic converter so I've attached three PDFs that should contain the info you need.

Exhaust Flexible Pipe Replacement (LF1).pdf
Catalytic Converter Heat Shield Replacement (LF1).pdf
Catalytic Converter Replacement - Right Side (LF1).pdf

webdawg

Thanks!!!

This will be my first time taking this thing apart. On the Flex Pipe Replacement it talks about removing the Front Lower Control Arm Bracket Brace. Do you have the procedure for that too? Or is it just simple?

Also do you have the Heated Oxygen Sensor Replacement - Bank 2 Sensor 2?

webdawg

I think I see what it is now. It is just a bar across the bottom.

I guess for the other I just need the torque on the O2 sensor for reinstall.

webdawg

I found the docs. Here.

webdawg

Does anyone know what it means to transfer both o2 sensors?

Do they mean measure?

ruley73

I'd say they mean transfer them with "transfer" meaning remove the oxygen sensors from the old parts and install them in the new parts as necessary.

webdawg

I get it now. That makes sense. Anyone want to confirm?

webdawg

So the reason I know my converter is bad is because I have had it in for diagnostic. That is, they observed a sensor 2 bank 2 'movement'.

After doing more and more research it seems highly unlikely that any o2 sensor is bad. A P0420 99 percent of the time means bad converter.

I think the cause, after reading, was the thousands of miles I drove with bypassed Mass Airflow and Airtemp sensors that are located in the air filter/intake box. They were bypassed because a Chevy tech did not tighten the clamp on the intake tube to the box.

This means that the engine was getting extra unmetered air into the intake and the ECM was compensating for this by dumping extra fuel into the intake for thousands of miles. This burnt that converter right up.

The reason I tell you this story is to ask:

Should I replace the O2 sensors also? The vehicle is at around 96k+anyways.

ruley73

I have a hard time believing that a loose clamp would cause the engine to receive that much unmetered air. If the air intake hose was partially or completely disconnected it would be plausible, but not with just a loose clamp. If you didn't notice much of a drop in fuel economy (as determined by actually calculating it; not just going off of the DIC reading) then it wasn't a very significant air intake leak and certainly didn't make the engine run rich enough to burn up your catalytic converter.

In your case all the oxygen sensors are identical parts. You could try swapping one of the other sensors with the one indicating P0420 to see if the issue persists. In my experience I've found that a P0420/P0430 code is usually caused by a bad downstream O2 sensor. This is comparable to a bad upstream sensor falsely indicating a lean running condition. A bad O2 sensor usually generates a lower voltage when they start to go bad. If the sensor is upstream the computer interprets the low voltage as a lean running condition and subsequently triggers a P0171 or P0174. If the bad O2 sensor is downstream the computer triggers P0420 or P0430. Most exhaust shops have the ability to sniff test your exhaust to confirm whether or not the catalytic converter is bad. The dealership should have that capability as well.