Is it Safe ??? Fuel Tablets

[Kytl68]

Just changed my spark plugs and found out that the fuel additive tablet that I am using has left a red/brown colour stain on the plugs .... it does not wipe off easily so not just some residue on it but more like permanent stain on the plugs (a little like light rusting).

 

I was by the mechanic that this is due to fuel additive and also the Denso plug reading picture also show the same thing.

 

I wrote to the maker of the tablet and they told me this is tested to be harmless and they also ask me to see that the plug are actually very clean except for the colour .... that is true, the plugs were very clean for 10K km old plugs.

 

But according to others, this will have some effect on the other components in the engine system like the O2 sensors, catalytic converter, etc. Since I have been using the tablet for more than 10 times, shouldn't it start to effect them already or should be much later ??? So far the engine light has not come on so I assume the O2 sensor is still OK.

 

I am not sure who I should believe Can anyone help ??? Anyone with past experience.

 

Do you think I should continue using the remaining tablets that I have ? Not use it since I changed the plugs.