Hi, I have a 2010 evo x. The car has a rough idle, and idles from 1k to 2k rpms non stop. The car also will not let me rev out past 3k rpms. Is this some kind of limp mode? Has anyone ever come across this problem? The asc and service required light comes on. The car will not stop doing this. Any help is always appreciated. Thanks

 

How long have you had the car?

What mods do you have?

What tune do you have?

 

It seem it entered some safety mode... My friends lancer does exactly the same: won't let he rev above 3k rpm (or was it 4k? don't remember) and it idles sometimes up to 2k rpm.

In his case, it is some lack of proper tuning after he turboed it with a ralliart setup.

Like Lightsaber asked, what are your mods? Which were the latests?

 

Car just has a full exhaust, intake, and blow off valve. Pro tuned. I just replaced my throttle body since my old one was broken. Does this new throttle body have to be reprogrammed to the throttle pedal?

 

I had a similar problem with my R32 Skyline back in the day.

I found that it was the MAF.

 

Maybe your maf sensor is all crazy since you replaced that. Or you have a massive vacuum leak. I would run some data logs to your tuner and see what he says!

 

Those are very prudent mods you have here. Like people said, check the MAF sensor. If no avail, take it to a shop for further diagnosis? Overall this shouldn't be any fatal issue.

 

Surely there must be a check engine light.

 

I would say relearn the throttle body first. then can check MAF second. throttle bodies can get sensitive

 

PCMs (atleast GM's PCMs) usually calibrate themselves at some "intervals", between fully open and full closed and then re calibrate its closed loop throttle control. IF you replaced the throttle body, try re learning the throttle. Also if it is in limp mode, they SHOULD be a code thrown by the ECU. Rough idle MIGHT be because of a dirty MAF. Try cleaning the MAF as well.

 

Problem solved! It was a bad throttle body. Thanks for the help!