If we default to down-voting the advice of others, simply because we haven't experienced it, we've lowered ourselves to the level of most other sites.
We should not down-vote, or remove, unless it's bad advice, in that it directly causes harm I.E.: "Pour 2 gallons of water in your oil fill tube and red-line your engine for 2 weeks."
The unfortunate thing is that we have individuals of varying levels of skill and experience doing the best they can to help someone with just a text based explanation. Often times the best answers are to simply talk about absolute basics.
"Is it plugged in?" should not be down-voted.
Another concept we should consider is that if a diagnostic tool costs X and the probable part costs many times over X, we should not be labeled whipping boys if we suggest it. Everyone loves to pick a extremist view on stuff like Fuel System Cleaner. When you start suggesting that someone replace their cats simply because they got a fresh P0420, You're more malicious than the "Run some premium through it" guy.
To remain on topic; Requesting that someone change their ECU could be considered an extreme without having first exhausting other diag options... But how are we going to balance that? We can only balance the fact that people should provide everyone with respect.
We can debate whether or not an expensive part is a solution, but why should we waste time arguing? In keeping with the "prohibit rudeness and/or maliciousness" we should make comments additive any time there is a concern that further diag should be attempted before defaulting to simply replacing a part.
I realize I am new here, so I suppose I have no say... But I feel it's important to stand up for those folks that sacrifice their time to be here and help others. Again, unless they are providing malicious advice, we should not be removing their comments/answers etc.
Those answers may help someone else who ends up here and has a slightly different issue but with linguistically similar symptom(s). Burying them because we have differing opinions is foolish.
I've left other similar sites before due to this rampant elitism, and complete lack of respect for users... I'd hate to have to leave this one, as well.
We all have some level of experience, and skill, which can prove helpful... If we start moderating people simply because we don't like the way they provide that information free of charge, with good intention, then this will be nothing more than a hive-minded group of individuals that assume that every problem can only be solved the way they deem it solvable, regardless if their solution is valid given the specific circumstances.
I feel that first-hand experience of an issue is highly valuable, especially when it comes from individuals who have experience solving highly complex issues with relatively basic solutions. Veteran Dealer Techs tend to have this level of acute experience and skill, and when they comment on other sites, they're often insulted, given that it seems oversimplified and/or irrelevant.
It is in my humble request that we do not devolve into a community of down-voters and hive-mentalists who only up-vote answers that we've seen favored, over and over again.
Thank you for your time.