My 03 montero sport 3.0 had the codes

p0300 random misfire detected
p0300 random misfire detected
twice oddly?
and
p0705 Transmission range sensor circuit malfunction

No one in my area knows Mitsubishis well so im gonna list what i can about my problems I know many models have these things in common when somethings wrong

mechanic says to replace my ignition coil to fix the misfire and that maybe the trans range sensor code would possibly wear off with the fix..

the car had a really rough idle and had a shudder around 20hmp (told was caused by the misfire from the dead coil pack giving no spark to plugs 3 and 6 and that my tranny fluid wasnt too bad) and a gas smell upon start up.. (i was shown the plus being pulled and i saw no spark going to that coil pack) when driving it also would make pretty much engine power loss noises just giving off that it was struggling to move at times almost a few minutes into driving it will also make a odd jerk if i try to drive slow to avoid my shudder at about 20-25 mph
It was clearly needing to be fixed i was so hoping the misfire would go away


i came home really late when i ordered from auto zone it so it was a dark out i replaced it with just my phone light so because of that i didnt bother unhooking the battery (if that would have anything to do with my issue.)



When i started the car it sounded different for a little and i had hope my problem was fixed it accelerated much better and my rough idle seemed to be less intesnse nearly gone it drove good and shifted better for about 10 minutes
not too much time passed and all my previous problems were back it was shuddering lots again i could barley really get past 20 mph because i felt that my power loss was going on again it would just shudder more if i pressed the pedal and i had a loud sputter and i assume the misfire in the same coil..

I assume im having the same problem again now what..
What could be going on did my coil go bad again suddenly? it seemed to work for a bit oddly?

I know nothing about this cars history but it seems to be in good shape and has the potential to work well clearly when it runs well

I have no idea how my plugs or wires are but i think this is a bit much from such a small thing on a car.. Just my opinion What should i do and check now? I need help.

Its just me and some basic tools so i cant do much besides small trips to maybe auto zone

Im curious if anyone knows if this is an easy fix i dont wanna risk driving to a mechanic yet i got the car pretty far away and near by ones seem a bit far too with my cars running state I feel its worth it.

 

If you are having the same issues with the new coil after it worked well at first, my guess would be that you are loosing a signal form PCM to coil. You need to check the ignition signal at the coil connector, at PCM harness connection and check the wiring. This does require slightly more sensitive electrical tools than normally found in an average toolbox. Have a mechanic do the tests. Honestly, the mechanic who did previous repair should have checked the signal to coil BEFORE replacing the coil. At the very least he should have swapped two coils on the engine and see if misfire stays on the same cylinders or moves to another pair. This is a very standard test that can be done in 5 minutes and doesn't require any new parts. If he is not very good with electronics, take it to someone else.

 

Replaced ignition control module all problems gone! got a new one for 40$ did the work myself totally worth it

 

Where did you get one for $40? What brand?

I'm debating doing this for my 3.5L as an attempt to address a P0306 cylinder 6 misfire.

 

I got my part off ebay not aftermarket brand (mitsubishi brand) found one for 40..

in my case spark plug wires that plug into to one coil had no spark and my car was running rough as ever on cylinders, only then i would replace the icm

do a few tests first if youre able to and get a few more answers