Fueling problems to No4 Cylinder

I've heard this cylinder can run lean and cause problems....
So when does this happen?
How can it be stopped?

Thanks

Walton

 

In not a mechanic but was speaking to one who recomended a sport cat downpipe as the full decat causes this, but that's could just be alot of rubbish, I would like to know abit more on this subject myself

 

I don't know how true it is, but I'd heard that it's mostly caused by the fuelling: No4 cylinder injector is on the end of the fuelling line, so can suffer from lower pressure and thus run lean. This in turn causes det, and piston melt, plus bearing damage.

One way to help alleviaite it is to fit a parallel fuel rail mod.

 

Any more info out there?