Toyota Hybrid - Burning oil and catalytic converter problems solved.I have taken a 2001 Prius to over 255k miles and a now a 2007 Prius to 272k miles but I recently found they can go a lot longer.
The 2001 had an ODB code of P0420 OBD-II Trouble Code Guide: Catalyst System Efficiency Below Threshold (Bank 1)
This was a real problem for me because I live in Californiai and I could not put in a reasonable priced after market converter. This also applies in New York, Maine and f you don't like spending money on a repairable catalytic converter.)
So I ended up scrapping the car and getting a "low" millage (202k miles) 2007 Prius. But soon of course it starting having the same problems. The 2001 Prius had a very complicated exhaust system with a carbon trap to trap the excess carbon produced while the engine warmed up. So I thought the converter would be way cheaper on a 2007 which has a much simpler exhaust system and solves the cold engine startup problem by storing hot coolant in a thermos bottle and does not start the engine till the hot water is pumped in the engine. To my shock the exhaust pipe with the catalytic converters was just as expensive for the 2007.
In California cars older than 8 ycars have to have their exhaust system inspected every two years. For my last inspection I used several catalytic cleaners you add to the gasoline. They worked and I passed the test but they did not permanently solve the problem.
I was having to add oil between oil changes so I knew my engine was burning oil and thought that was the actual cause of the problem. One company I talked to that restored catalytic converts by cleaning them would not do it if you engine was burning oil.
This confirmed the problem was the engine was burning oil. I thought the only solution was to replace the engine. Needless to say a big expense. Then I talked to:
3790 S Western Ave Unit B
Los Angeles, CA 90018
Based on Avi advice and other data I put together the following procedure:
- Park the car level. For drainage reason most outside lots are not level. However you can level the car by letting out air and pumping air in the tires.
- Take out the spark plugs.
- Pour in 1/4 a can of seafoam motor treatment (or carbon cleaner of your choice) down each spark plug hole.
- Hand crank the engine a few turns. On a 2001 to 2009 Prius you have to take the air intake manifold off to get to the pulleys.
- Put the spark plus in a few turns to keep dirt out of the cylinders
- Let it sit for three days or possibly just over night (see note *)
- Then unplug the fuel injectors.
- Unplug the ignition coils to prevent any sparks.
- Take out the spark plugs
- Drape a lot of rags over the top of the engine to try to capture the sea foam when it comes flying out of the engine. (Seafoam does not seem to hurt plastic rubber or paint.)
- Crank the engine. The disconnected plugs and coils will generate a lot of error codes but before they do the engine will crank very fast and the seafoam will go flying.
- Put your spark plugs and ignition coils back in.
- Plug the ignition coils back in. The cords are not long enough to mess up and there is also a white gray white gray pattern.
- Plug the fuel injectors back in. (again the wire harness prevents you from doing this wrong)
- Put the air filter back on.
- Let the engine idle.
- Change the oil right away as too much of the seafoam might have leaked into the oil.
* I power cranked the engine (which ejected most of the seafoam) and just let it sit overnight and that still seamed to solve the problem but was not entirely sure. Since the oil ring is the lowest ring, I also put in an engine flush in the oil. That I did the easy way by going to Walmar. Checking to make sure the was not too long a line for oil changes. Buying a bottle of engine flush adding it to the oil, letting the engine idle and then having them change the oil.
After the overnight with seafoam and the engine flush my 2007 Prius with 270k miles is not burning oil and the oil is staying clean.