My 2005 Magnum sxt (3.5L) has intermitant warning lights which look like a lightning bolt between two reversed parentheses and the bas light. when it comes on the car won't accelerate, bucks and when stopped, idles erratically. After sitting awhile, it goes away and everything goes back to normal.

 

Thats the warning light for Throttle control. Sounds like you need to make a trip to the dealership.
It is usually a Bad PCM, 8yr/80k waranty.
But it could be a throttle body too, but For magnum, Usually it is a Bad PCM. depending on the code.

unless they found something like vacuum leak or Wiring problem, usually it is either one of above.

If the dealership tries to sell u a $800 Throttle Body, but ur PCM is still under waranty, talk to ur Tech, and Stick $50 bucks in the Mechanic's pocket and tell him to try a PCM first.

 

I got the auto tech instructor at our high school's career school to read the codes with his computer today. It came back with two readings: P0406 & P2173. One is for a vacuum leak slow accumulation and the other is for egr high setting. Since Mike is super sharp on his machines he's on the mark with the vacuum leak idea. I had the plugs replaced about 2 months ago and this never happened before. I'm inside the 8 years on the throttle body warranty but about 15k over the mileage.

 

EGR high, you'll need an EGR valve.

Vacuum leak wise, maybe one of the Hose or Intake gasket is damaged when u pull off the intake manifold for a turn up. And yes, it can cause the PCM to think the Throttle body is bad.

Or maybe if your intructor got smoke machine and smoke the intake for leak.

 

Well, the check engine light came on permanently. A quick code read by our auto tech instructor showed an EGR malfunction. The lightning bolt was apparently caused by the feedback by the EGR. Took it to Hoover Chrysler Jeep in Summerville, SC. Gave them the codes, the reaffirmed them, replaced the EGR, and $427 later the Magnum is running great again and the mileage is back up in the mid to high 20s mpg. Not bad for a 3.5L v6. thanks for all the suggestions and info.