Catalytic Converter Safe Oil?

[AdmiralYoda]

I've bought and installed plenty of aftermarket cats without issue, I would give it a shot. But the oil consumption issue is still going to be a problem. A prolonged piston soak and maybe start using a quart of HPL's cleaner oil and do some short oil changes to clean out any gunk in there and clean the rings.

Here is my recipe for a weekend piston soak:
1. Let the engine cool Friday afternoon. Take out the spark plugs.
2. Pour in a few ounces of Berryman B-12 into each cylinder. Repeat a couple times each day.
3. On Sunday afternoon squirt in a penetrating lubricant like PB Blaster in each cylinder. I just don't like starting the engine up without lubrication on the rings and cylinder walls. I am unsure if the B12 lubricates, so the PB Blaster eases my mind.
4. All of this stuff will end up in your crank case so change your oil.
5. With the spark plugs out, crank your engine a 2-3 seconds to get rid of any excess B-12/PB Blaster in the cylinders in case there is some that didn't drain for some reason.
6. Install new spark plugs and start it up. Go for a spirited drive and let it run for as long as possible. Take it on the highway and get it good and hot.

Do some short OCI's and maybe repeat the above process a few times. There are also some oil additives out there that do some serious cleaning but I'd try this first.

 

[Ashraf Jaafar]

https://comparemotoroils.com/amsoil-xl-vs-signature-series/

 

[chrisgraham]

I have a Chevy Equinox with the infamous 2.4L Ecotec nearing 200k miles. It's a great running engine and I just replaced the timing chain last year. The transmission and body are in good shape so I have no plans to get a different car any time soon.

Now onto the problem: the check engine light came on a few months ago for catalytic converter efficiency then went off within a couple days. It came on a few weeks ago and stayed on. It burns about a quart of oil every thousand miles and has done so for the last 120k miles. I can only assume that the countless quarts of oil being burned and sent through the catalytic converter has damaged it to where it doesn't function anymore. A new cat from GM is roughly $900 before tax, the aftermarket ones never seem to work or last and of course a used one isn't an option.

So, I'm wondering if there is an oil that is less detrimental to catalytic converters? I know there's oil that is worse (ones that contain high zinc like Redline) but I'm not aware of any that are less harmful to cats. I was thinking possibly PUP made from natural gas might burn "cleaner" if that makes any sense.

I just can't see taking on a $600+ car payment for the next 5 years on a 2024 Equinox when I can keep this one going for far cheaper. I think I've averaged $50 a month in maintenence and repairs over the last few years. I do all my own work so labor is free, parts are cheap and easy to find. I'd also have to learn all the problems and shortcomings of the new body style when I'm already well versed in the 2010-2017 generation. I'm also concerned with long term reliability of that 1.5T with stop/start and all the electronics the new ones have. The 6 speed carried over from the '10-'17 gen so at least that's familiar.

The short answer is no oil is going to manage the problem you are having. It's pretty late in the life of this engine now, but if it were mine, I would be doing a piston ring soak / engine decarbonizing followed by a conversion to Valvoline R&P to see if I could reduce the amount of oil this engine is burning before putting a new cat on it.

 

[dubber09]

Pennzoil Euro oils, at least some, and to my knowledge, are same as Shell ECT line where ECT stands for 'emissions-compatible technology'.
Example - Pennzoil Platinum Euro LX is same as Shell Helix Ultra ECT C2/C3. I think the line was developed as an answer to Mobil 1 ESP line.
Shell claims the oil to be '...our most advanced formulation to date..'.
https://www.shell.com/motorist/oils...-ultra/shell-helix-ultra-ect-c2-c3-0w-30.html

 

[addyguy]

Castrol HTX High Mileage oils claim to have reduced phosphorus to reduce CC contamination.