High idle 1300 rpm chrysler concorde 3.5 1995 after i changed 6 injectors

Test for vacuum leak

sounds to me that you have a vacume leak on the engine.

yes any vacuum leak with increase the idle

sounds like you have a vacuum leak some where, did you leave vacuum hose off, did o-rings on injectors seal ?

High idle is usually caused by a vacume leak. First place to check is the cold air intake manifold. All hoses, throttle body, and sensors. Throttle Position(TPS), Mass Airflow(MAS), Idle Air Control Motor (valve) IAC. Controls Idle speed

A malfunctioning throttle system can cause both a high idle as well as an engine stall.

A dirty air intake or cracked air intake tube is often the culprit.

How to Fix an Engine High Idle in Under 15 Minutes

Maybe a short to the TPS or something shorting it out. There's also the IAC that really controls the idle but usually it will cause the RPM's to go up and down a little erratic if bad. The MAF sensor can cause major problems as well but since you already swapped the TPS and it helped and then stopped I would focus on that sensor and especially it's wiring to and from the ECM. Be careful with the sensor signal wire to the ECM can blow it if more than 5v passes or spikes.

have you checked for vacuum leaks?

when you say its leaking,and you replaced the O ring,are you seeing a fuel leak,if so where at?
is it coming up from O ring or the injector its self ?
did you remember to clean the hole where the O ring seats.

mcdevito75 here, It could be the air idle sensor or motor, have your shop run a scan or change this air idle motor / sensor.

with a 2002 Concord 3.5 V-6, what should the rpm be at 60mph? 70 mph?

I'm not sure if the overdrive gear is lost in the tranny, but the transmission light is on.

Thanks