2000 chrysler concorde 2.7 timeing went out sat 1 yr put new chain all intake valves have car running but miss at 38000 rpm and wont acelerate passed 4000 rpm cleared codes at times po171 pops up has heavy hesitation at 3800 and 4000 but runs ok any where before 38000 rpm

It's a BIG job. It requires removing everything from the top of the engine (intake manifold, throttle body, all plumbing, valve covers) then removing the harmonic damper, most of the accessories, and then the timing cover. That's just to get to the timing chain. You have to remove the chain guides and tensioner, then cam gears and crank gear. If you're going this route, also replace the two chains (intake cam to exhaust cam) on top of the heads, the water pump, and the tensioners. Be very precise in reinstalling the three timing chains so that everything is in time.
The link shows the details of the chain itself, but be aware that your engine is packed into your Intrepid with limited work space in some areas.
Chrysler Sebring Concorde 300 2 7L timing replacement Cloyes kit 9 0397SA

Test the fuel pressure regulator. It has a check valve in it to maintain fuel pressure when the engine is not running.

rpm sensor bad this keeps the car from over tacking.

i would say your best bet is to clean out your idle air control valve. sounds like its getting stuck open or closed

The timing marks are not properly aligned or the distributor is not aligned properly.

You'll need to get a service manual for the exact settings, make sure that after you set the marks you rotate the engne 2 complete revolutions & recheck the marks prior to reassembling the covers. Double check the distributor timing as well & check for any possible vacuum leaks from hoses or gasket problems.

If your chain had broken originally, then you possibly have some upper engine valve damage that will have to be diagnosed. A compression test will reveal any bent or broken valves.

good luck

Check intake gaskets. Pour warm soapy water on the gasket when it's running. If it bubbles like crazy, you have a leak. 2. Check timing. Shoot a timing light at the crank mark. If it jumps around a lot, your chain has jumped. #3. check cam. Remove valve covers, run the engine, and see if they are all raisng the valves the same. Put a piece of cardboard along the bottom, and fold it around a little, so it forms kind of a " half valve cover". That way you won't lose oil everywhere, and make a mess, or a fire.

change the plugs and wires.

There should be plated links on those chains too. There is an index dot in both cams on each head that set at the twelve o'clock position.

Hope this helps

I have a similar problem. I just replaced the water pump and now the POS wont start. Like it is not getting fuel>