timing chain tensioner

i put up a post acouple of weeks ago, "rich on both banks"since then i had a weird knocking noise just when i first hit the accelerator ever so slightly when taking off.Took it to the dealer twice and was told catalytic converter. Went to the muffler shop and was told it was coming from the motor.I brought it back and asked for a supervisor and told him what was done.He didn't even listen to my vehicle and asked me if it was a V6.I said yes and guess what it was my timing chain tensioner.$1400.00 later and my truck runs like new. He said they have done 6 vortec v6's in the past year with engines around 90-120k on them . Unbelieveable. So if you have a v6 and start to hear what sounds like real bad detonation or a rod knock have your timing chain and tensioner checked first.LOL