Blazer Forum - Chevy Blazer Forums - #5 plug Carbon Fouling out only !!

Guys I could sure use some expert advice here .

96 S10 Blazer with a 4.3 and the #5 plug only keeps fouling out covered with Carbon Fast and by fast I mean within driving a couple of miles !

Had a set of Champion plugs in it from last tuneup 2 years ago "oldest son did it as I was down on my back" and I just figured it needed the AC/Delcos so I put a set of the Rapid fires in which Oreilys said was the correct plug and it lasted a few miles then #5 fouled out , then I did Rotor cap and wires not Delcos,s but not cheap Autozone specials either wires alone were $70 and Cap and rotor are Berg Werners about $40 for both .

Had it inspected and its throwing that code "PO350 which I knew since I have a scanner tool" and one that is saying O2 sensor overheating which the mechanic told me was all probaly caused by needing the complete tuneup and it didn't fix it after I had done it . Had them "NTB" do a diagnostic for $50 and all the kid tells us is it is a fouled plug which I already knew "total waste of time and $$" he has no idea what's causing it .

Less than 2 years ago it had a set of new injectors installed and the fuel pump replaced + filters etc .

Called a Chevy dealer Service dept .to see what they charge for a diagnostic and explain what problem is and he tells me it just fouling 1 plug that fast makes no sense to him at all !!!

Even when the plug is replaced the engine stills runs a bit rough and you can feel it but not too bad , honestly after the plug fouls out it seems to run smoother LOL .

Nothing on the plug other than carbon no gas smell or oil , nor is the plug physically damaged "other than electrode covered in Carbon" , anything yet now a couple places I called said it could be faulty injector even though it is almost new at less than 2 years old .

Help !! at $100 an hour for shop work I don't want to give it to someone who thinks I am a cow and they're gonna "Milk" me for more than I have to pay to get it fixed .