Something strange about my Evo this morning..
I turn it on, let it run for 5 minutes, and take off... I turn heat on, and I can smell something funny, it smelled little bit sweet, but just for a minute or two... I drive it for 3-4 minutes mostly in 3rd or 4th gear, when I shifted into 5th gear, the serving engine soon light came on... I dont know what could it be... I took it to a Mitsubishi dealer, and I set an appointment for this thursday... I just hope it has something to do with drivetrain, beacause of the warranty.. But my question for you guys is, what could be the problem...
-- Last time I put in the gas was on Saturday, and today is Monday.
-- It was raining outside, and temperature outside was about 45 to 50 degrees
-- Car temperature was as usual
-- Car sounded lil bit lauder (just enough to notice), I think because of the cold weather..

 

Take it to Autozone and have them read the code. They will do it for free.

 

ooohhh yeah.. nicee.. gotta check it out..

 

So I went to Advanced Auto Parts and I checked the code... The code was P0420 and under it said Catalyst Efficiency Below Treshold... So something is wrong with the Cat, I only thought maybe it got apart somehow, but today the light went off.. My exhaust seems like it shakes a bit when I drive.. I just gotta lift the car up and see whats going on under... I dont think it's necessary to go to Mits dealer and do a diagnosis test..

 

Do you have the BOV VTA?

 

get a CEL fixer from Gruppe S or lancer shop all it is that according to the O2 sensor in the back your cat is not taking enough out or not being restrictive enough what these do is pull the sensor a little out of the exhaust stream and tricks the sensor in believeing there is a good cat there not a high flow or a test pipe mine did same thing fixed now if only that thermostat didnt throw a code now....

 

I dont have BOV.. car is bone stock...
I was gonna go to dealer and do the diagnosis test, but the light went off after 2 days.. so I decided not to go... The exhaust shakes a lil bit, so I just have to look under, but I did not have a chance yet.. Today, is raining, and after 5-10 minutes of driving, the light came back on...

 

damn..thats weird coz i got a similar issue. engine service lights on in off on mee'.i just got all these mods install on my car

 

Maybe some of the internal honey comb in the cat had fallen apart? More flow = CEL light, also could cause it to be a bit louder.

I'd unbolt the cat and have it checked out.

As far as the sweet smell, that sounds like coolant leak. But who knows, since you said you didn't notice anything to do with tempurature or green spots in the driveway.