just a couple of days ago i got into my truck to go to work. i started it up and everything was fine. i then put it in drive and it started making an awful ticking/knocking noise. it only happens in drive and reverse. took it to a buddy of mine and he thinks something in the catalytic converter on the passenger side has come lose. to me it kinda sounds like something stuck in the front driveline. almost like a bad axle but they all seem fine and it is definitely a motor/exhaust problem. i would think that would make the noise all of the time. i havent driven it since because i dont want to do any damage. it has just over 152,000 miles. thanks!