2001 Mitsubishi montero sport, RPM's won't stay high enough for car to run All we did was replace the battery

Question edited for clarity.
Question moved from Misc to model category.

https://www.justanswer.com/mitsubishi/9nxqo-mitsubishi-montero-xls-crank-sensor-located.html

Just close the chat box on the right.

https://www.google.com/search?q=2001+mitsubishi+montero+sport+crankshaft+sensor+location

Hello fixya why all your question is about montero 2001.

I doubt it is the belt because if the belt is slipping you should hear it.
The alternator could be about to crash and not charging at lower speeds.
You would check alternator output to find out.
The battery and brake warning lights are on the same circuit.

brake light switch probably bad and probably is the idler pully.

CHECK ALTERNATOR DRIVE BELT COULD BE LOOSE NEED ADJUSTING OR GLAZED NEED REPLACING. IF ALL IS GOOD, CHECK ALTERNATOR VOLTAGE OUT PUT AT BATTERY SHOULD BE 13.5 - 14.5 VOLTS. IF NOT ALTERNATOR FAULTY BUT CHECK ALTERNATOR BATTERY FEED AND VOLTAGE REGULATOR WIRES FOR LOOSE CONNECTION OR DAMAGED FRAYED WIRES. CHECK ALTERNATOR FUSE.CHECK THOSE THINGS BEFORE BUYING NEW ALTERNATOR.FIRST TURN OFF RADIO BEFORE DISCONNECTING BATTERY CABLE TO KEEP FROM LOCKING OUT RADIO.

run the fault codes
possible a vacuum leak
when it happens, leave in drive apply the handbrake and take the foot of the brake
if it fixes the problem . replace the brake booster

need radio code for 2001 Mitsubishi Montero sport. Serial number J44mT21H91P001563. I replaced the battery which reset the radio. My email: [email protected]

is ac low side pipe/hose cold?(large line)near firewall? if so u have a temp door actuator motor not working

your code is 1867

nope had the same problem with my 98 montero sport, change your PCV valve, cost less then 3 bucks