I don't know about diesel, because as was pointed out, diesel injectors get
cruded up.

One mechanic says the best injector cleaner is ATF, because it's super
detergent or someting.  My father uses it on a (non O2 sensor) diesel engine
with quite noticable results: rough idle smooths right out.  He probably
puts in a liter in every tenth tankfull or so.

I've used it before in my 1.9L and believe it gets the job done, but I too
have concerns about the effect on the O2 sensor.

Any AUTHORITATIVE, KNOWLEDGEABLE relpies to this O2 concern? (yep, that
means jokers like the majority of us have NO SAY in the matter)

Alias Fred