I have an evo 8. The car has open exhaust and filter. For a few months ago it was taken to a shop for some underbody work (rust treatment)
They took down the exhaust system and I've noticed a slight leak of exhaust after I got it back. It was damaged during the work.
The car has always had an uneven idle, and a few times it could happen that it would stop. Today I was changing my batteri, and the idle was running normal when it was cold, but at normal engine temp it stopped and would not run at idle without me kicking some throttle. Any ideas?

 

Powerstroke... forgive me, as I'm not certain the Norwegian cars run the same type of recording... but is it throwing any check engine codes at all?

Does the car have a proper tune on it? And when you say open filter... what exactly do you mean? Do you mean that the stock airbox was removed, and replaced with a cone filter, but still left the stock snorkel (crinkly hose between the mass airflow sensor and the turbo) and the mass airflow sensor in tact? Or was the snorkel replaced with a smooth metal pipe as well?

 

No warning lamps at instrument cluster. Haven't checked for codes. Have no instruments for it. I'm not to much of a motor guy, guess i have to take it to a shop.


The filter looks like this:

 

Yup, could be the MAF, or a tune issue, or even a leak somewhere. If you're gonna take it to the shop, take it to someone that has experience with the Evos.

 

When my car did the same thing, my issue was the IACV. Replaced it and would hold idle again.

 

What is the best diagnostic scanner to buy?

 

Looks relatively stock.

Powerstroke... EvoScan and a tactrix cable is probably the best bet, but if you aren't really mechanically inclined, I might advise against purchasing one. You can cause lots of damage with a few clicks of the mouse.

Whats the backstory with your car? How long have you owned it, and whom did you purchase it from? I might suggest taking it to a reputable tuner to have them investigate. Chances are, since you're running with no catalytic converter, your car has the check engine light disabled... so it may not throw any codes.