I think it would be a better idea to simply get a newer car.
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I have to check this again. I recently changed the PCV valve and this has significantly reduced the oil burning.
If I had to guess, it would be less than half a quart every thousand miles.
One quart of oil per 2 thousand miles is fine, not considered burning oil. Even as much as one quart per 500 miles, some manufacturers consider that normal. The fact that your oil usage reduced significantly after replacing PCV valve suggest the oil burning problem was caused by the pcv system was sucking too much oil from the crankcase. One of the pcv valveās functions is to prevent that from happening. If you are diyāer inclined, suggest to Google the common diyāer method for checking the pcv valve. Simple test for most cars, takes less than 5 minutes. I usually do that test myself, at every oil & filter change. Or ask your shop to check the pcv system every time they change the oil and filter.
While the PCV valve was allowing too much crankcase oil flow, that could have damaged the cat, and it could also have gunked up the throttle body. If you continue to have difficult to diagnose symptoms, esp loss of power, difficult to maintain constant rpm, engine stalling while idling, make sure your shop is aware of the PCV problem.
If I needed to replace a plugged-up cat on a car which burns oil, Iād keep the used one and ream it out with a broom handle, shake out all the bits, and reinstall the hollowed-out casing. Only when itās time for emissions testing would I (temporarily) install the new one, long enough to get the car through emissions. Then Iād unbolt it, reinstall the hollowed-out one, and save the new one for the next emissions test.
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Donāt do as suggested.
Instead, recycle the old cat.
You can get $100-$150, depending.
If you bust it up, youāll get nothing.
Tester
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I wonder how often the āinstall the good cat just for the emissions testā technique is used? It seems like a lot of effort would be involved. And it would have to be done well in advance of the emissions test on OBD II vehicles, to allow enough time for the cat readiness test to pass. Not to mention if a car owner was caught doing this, could be a pretty big fine.
On some cars, itās super-easy to unbolt. For example, on the Daewoo Lanos or first-generation Chevrolet Aveo. After years of driving my Daewoo with engine mechanical problems (since repaired), now the CEL is on for P0420.
This car does not burn any oil, and the cat is not plugged up. When itās time for emissions testing, I am going to unbolt it and try cleaning with carburetor cleaner. If that doesnāt solve the problem, then I will just buy a new (aftermarket) cat.
However, if I had a car which I know is consuming a lot of oil, and the cat was failing because of that, reaming out the old cat, and temporarily installing a new one to pass emissions would really be a no-brainer. Whatās more effort? To pull the motor and transmission and install new pistons, rings, etc, or to swap a catalytic converter once a year or once every two years for emissions testing? Time is money, right?
I seriously doubt anyone here is going to openly agree with your approach to āpassingā a smog inspection
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