BTW, one thing that came to me loudly and clearly after reading the Witchhunter site was that cleaning a fuel injector is a lot more than just dumping a can of snake oil into the fuel tank every 3,000 miles!
The site says that "effective" cleaning can not be done while on the car, which I would tend to believe.
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Here's what the FAQ says, verbatim, on exchanges:
Why doesn't WitchHunter Performance offer an injector exchange service?
We only clean our customers injectors, that way you know what you are getting. Some companies buy old used injectors by the truckload, use minimum wage labor to clean the injectors that work and throw the rest away. So you may be getting one with 30K miles and some with 400K on them in the same set. It is common practice for these places to grind off the original part number and give you an injector that flows "close" to your injector.
So, what I gather from this is the following assumption:
- You give them YOUR injectors
- So does another customer, and another, and another
- They clean and test YOUR injectors (and that of the other customers)
- If any of yours need to be "replaced"; they take them from the other customers' injectors
I guess what they do not do is buy injectors in bulk and use them for the matching - but apparently they do use other customers' injectors to substitute when the need for matching arises.
Do I have the basics of "matching" understood yet?