Hey guys I've noticed lately on my 03 TL-S that I have a slight drone coming from the exhaust. I mostly notice it when accelerating and setting the cruise at 60mph where I get this humming/drone. When I let off the gas the drone stops.
Now I'm noticing that the rpm's are fluctuating by 2 - 3 hundred rpm's. I can see the rpm gauge jump around a little bit when I'm set at a steady speed.

I find this really annoying and want to get it fixed. I went to an exhaust shop and they put it on a lift and put the car up with the engine on. The mechanic noticed the hum/drone was coming from the flex pipe and I also heard it. But when I'm driving I can hear it coming from the rear of the vehicle not really anything in the front.

Anyways I'm about to drop 160$ to get it fixed although I wanna know if the rpm fluctuations can be the culprit of the bad flex pipe??

I have 125k, everything has been serviced/ the only thing original left is the plugs!

 

I have read of flex pipe breakage possibly related to broken motor mounts

Having an open exhaust leak invites cold air to be sucked into the system- not good!
can cause burnt valves and worse
an rpm variation is likely as well

Get it replaced- welded- whatever, but from gas cap to air filter box lid and thru the tailpipes is a sealed system,,or should be

 

throw a can of seafoam in half tank of gas and get some new NGK Iridium or Iridium IX plugs and install them-
125 on OE plugs--(shaking head in disbelief) what are you thinking?>!

 

My plugs were changed at 24k but since then they have been clean as a whistle! I've never had any problems with anything motor related and yes flex pipe will have to be welded ASAP!