Back Ground:
I have had issues with my car stalling when I allow the RPMs to fall down to idle when lets say I come to a stop. Every now and then the car will go into limp mode, with a code of P2135.
I have cleaned my MAF a couple of times and the TB once (although not very well). I have also replaced the accelerator position sensor and still have this problem.
Since I have replaced the accelerator sensor I have reset my ECU, and I had given it plenty of time to relearn.

Now my idle problems have not been fixed. The idle will sometimes be normal, sometimes "bounce" starting at 500 to 1500, then 500 to 2000, then 500 to 2500, then 500 to 3000 and will continue to 'bounce' between 500 and 3000 until I restart the car.
I will still occasionally still go into limp mode and receive a P2135 code and today my car went into limp mode on the hwy, and I pulled a P2100 code.

I will be thoroughly cleaning my TB today, and I am hoping this will fix the problem, but I would like to hear some other opinions on what it could be.

 

That code is associated with the accelerator pedal position sensor. It seems yours is on it's way out.

 

But I have a brand new one. Bought and installed less than one week ago.

 

says throttle position sensor in the list, is that not inside the throttle body?

also, there is a correlation between the accelerator pedal position sensor, as well as the thing in the throttle body, obviously they should be working together, proportional to each other, if there is poor continuity, like improper resistance/voltage you will get a code. Also, i read something in the manual about calibration of the APPS.

 

I recently swapped my APPS as well but none of those are the codes I was getting. I think a lot of CEL readers just give generic names for problems. Since your APPS is new I would go a bit deeper. I looked at a daigram of the throttle body at the Mitsubishi dealer near here and there is a chip on the throttle body that could be giving you the issue.check and clean all your connections. And look into the that chip if its messed up and sending the wrong signals it could be the culprit behind all your issues.
Best of luck!

 

Did cleaning the TB today help?

 

I was able to clean it this afternoon, and so far I haven't had any issues. I will know more tomorrow.

When I installed the APPS I also slightly tightened the throttle cable because it had noticeable slack (not enough to be tight, but enough t remove any slack). I loosened the cable a little bit when I cleaned the TB as well.

Hopefully I do not have any problems tomorrow.

 

So after driving for a bit longer, the car would still stall out, but no other problems. I reset the ECU again, and now it is running perfect!!

Thank you for the suggestions.

 

throttle cable is supposed to have a bit of slack

 

Well since this thread is named for the exact thing Im wanting to ask about I'll just post my question here:

I noticed a couple days ago that sometimes after Ive been driving a little while and come to a stop my RPMs will drop to about 600, the engine obviously idles a bit funny when it does this. Should I be concerned about this?

 

Normal idle is 800 when the motor is up to temp, so I wouldn't be too worried about your idle at 600. Especially if it is not causing you any problems.

I would try a good TB cleaning. I believe it fixed most of my idle issues.

 

have the same prob...

 

Yeah, I believe that's normal. At normal running temp. my car as well sits at 600-800. *shrug* No worries.