I'm sorry to hear about your problems with this but as I said before, there's really no better way ("to my knowledge, at this time") to go about solving a problem like that. If I had a "parts car" handy (like a used '94 turbo 850 on the lot, not a customers car), I'd prefer to start with trying a control unit swap first to see if that cures the problem BUT unfortunately, we don't always have those oportunities where I work in every situation either. Parts departments won't lend out new control units, they must be purchased and those aren't cheap, so usually the cheapest first step is to try the newer style knock sensors and hope for the best. It's also very intermittant so no immediate fault tracing does any good, the code can be cleared and might not return for weeks.
Although it was a costly journey and I'd be upset too if that was my car, at least that problem should now be solved.
|