UKMyers

I noticed today that under heavy acceleration I am getting a small pinging coming from the engine. I am running 91 Octane fuel but I hear that it is crap here in the UK. Is there a chance that by adding my K&N and Borla Catback it has changed the timing a little bit? I have read in other threads that the timing is very critical in the 3.0. It runs great, has plenty of power(well for a 3.0 anyhow) and idles fine. I was taught early on if something is working don't mess with it but I just hate mystery noises in my truck. Going to try an octane additive first and see if that cures it but curious if anyhow has some inputs that has messed with their timing. Thanks