Overtures to NHTSA (by Spyderchat, et. al.) have been rebuffed based on the "safety" issue (frankly, I think an engine suddenly disintegrating DOES have safety implications), so it seems the EPA should get involved given the environmental considerations, appropriately highlighted in several other comments. I've focused on that angle in at least one blog post: http://uc2.blogspot.com/2013/10/toyota-told-to-conduct-awareness.html
Not that I condone tampering with emissions devices on newer vehicles, but on a 1987 I would take off the cat and empty it. Put the shell of it back on the car for appearances.
I look at it this way, there are very few old cars running around and that number is dwindling. A few here and there with some of the emissions surpressed is not as big a deal as new cars not working correctly. In the case of this Spyder, they were crapping out with very few miles on them! Unacceptable. As a previous commentor pointed out, the engine failure was an even worse enviromental hazard!
Catalytic converters ARE a caution, in my 1987 Volvo wagon, the 'orange' of catalytic material came loose inside the converter shell. It wasn't too much of a problem on level ground, but it would roll back and plug the catalytic converter outlet when going uphill....Talk about loss of power! Pulling over, and reduced exhaust from the engine would allow the 'orange' to roll away from the outlet, engine would run just fine- It took a while to figure out what was going on!
The point of installing environmental controls is to lower the waste and effects on the environment.
At some point, we have to ask whether there is an environmental return on the investment. Here we have entire engines self-destructing after only 30k miles on them. How environmentally sound is that?
Please don't misunderstand me, I'm not ranting against environmental controls, I'm only trying to find the most efficient way we can deal with the methods themselves without causing undue harm to the environment just by it being there.
tekochip, I also found information related to incorrect bore and hone of the cylinders that may lead to an incorrect break in of the rings. This leaves the bore oval and oil bypasses the rings and settles on the precats. The burning off of the oil may lead to the precat failure. Toyota changed the bore and hone of the cylinder late 2002 early 2003 (no one is quite sure). This seems to take care of the ring break in issue. Many also speculate that the precat was revised at the same time. Seems Toyota isn't really saying and most of what I found on the web is conjecture and theories.
One universal on the web, the failure is catastrophic. Other recommendation, take off the exhaust manifold and knock out the precat! I have seen recommendations to do this to the newer models after 2003. Seems that the engine will pass emissions when at operating temperature (mandatory lawyer clause of not responsible for this information if you fail your emissions test).
Great post - explains the "ins and outs" (pardon the pun) very clearly from a technical perspective. Especially informative since the question has come up in other forums as to how material from the pre-cats finds its way into the engine. Thanks for your help.
That's a very good description of the problem and how it affects the vehicle, Tekochip. This seems to be a widespread problem with this model. A quick Google search found tons and tons of references to pre-cat problems.
Another example of complex systems failing in complex ways. As the pre-catalyst fails you would think that the exhaust gas pressure would keep all the containments from flowing back into the engine, but the MR2 engine features variable valve timing. Under some conditions the valves change their timing to allow a little exhaust gas back into the cylinders, sort of a vale timing version of EGR. So, with the variable valve timing sucking in exhaust and the pre-catalyst failing, the result is containments scoring the cylinder walls and valves.
Festo's BionicKangaroo combines pneumatic and electrical drive technology, plus very precise controls and condition monitoring. Like a real kangaroo, the BionicKangaroo robot harvests the kinetic energy of each takeoff and immediately uses it to power the next jump.
Design News and Digi-Key presents: Creating & Testing Your First RTOS Application Using MQX, a crash course that will look at defining a project, selecting a target processor, blocking code, defining tasks, completing code, and debugging.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.