sorry i am new to the forms but i need some help. i just bought my evo x and it through a check engine light today. i got the code read at auto zone and the told me i have a bad o2 sensor and miss firing. its also idles really weird. is there some thing i can do or do i just take it to Mitsubishi and let them take a look at it. any suggestions


parts list:
manley rods
manley HD springs, retainers
manley pistons 9.0.1 86mm w/pins n clips
ARP head studs
kelford st.2 cams
cosworth gasket, rod, and thrust bearings
Garret gt3582r w/ v bandhousing and down pipe
custom headers
ets highflow cats and v.2 quiet exhaust]agp 3.5 intercooler
1100 injectors
and so much more...

 

well this miss fire would tell you why it idles the way it does. miss fires can be alot of things was it a specific cylinder or was it a random cylinder miss fire code?

 

What specific code was it? Nismo n9ne is on the right track. Also, check your plugs.

 

Did you tune it yourself? Is it a used modified evo x? Did you buy it from the dealer? If the dealer sold you the evo, you can return it back. If it was a private party sale I guess you need a local tuner to fix that.

 

it was tuned by motion lab and no it just said miss fire on the scaner at auto zone. im going to the dealership in the a.m and hopefully its just the o2 sensor thanks for the suggestions

 

go check with the tuner first and then try with o2 sensor

 

How long have you had the car? Is it a new tune? If you've been driving on that tune for a while, has the weather significantly changed to hotter temps?

Is it the rear or the front o2?

 

A misfire code would be related to the spark plugs, not the o2 sensor. An o2 sensor would be a different code...maybe you threw both? A rough idle would also be spark plug related but probably not o2 sensor.

 

Cpt. Obvious is going to point out that if it has pistons and rods, and he's saying he just got it we can deduce that:

1) He went to Autozone to have the code read, it's safe to assume he did not tune this himself and probably doesn't know anything about tuning, or he would of already been datalogging

2) He bought it used and modified

3)
a)Even if it did buy it from a dealership it's likely going to be sold as-is.
b)He wouldn't have a complete parts list including piston specs and a larger turbo unless the dealership knew it was modified, reinforcing a "sold as-is"


My best advice, avoid the dealer, they will be in clueless-land because the engine was touched. Hit up a tuner that can datalog and get a good analysis of what is going on. From there, if it needs engine work, hit up a performance shop. It's not like you're fighting to keep a warranty at this point. Most performance shops will give you more qualified service at a better price point for already having a built engine. If possible hit up the seller to find out who did their work, so you can take it to someone familiar with it.

 

This.

 

Also, I don't know how far this is.. but Cobb is in Plano, TX. Again, I don't know where that is compared to where you are, but I would DEFINITELY trust my car there with them.

EDIT: Just checked, that is like 3.5 hours.

 

Still worth a trip if you know someone with a truck that can tow you on a trailer...I mean I've only been to TX like 3x, but seemed like everyone had a diesel 3/4 ton truck

 

What I was thinking earlier when I suggested to check the plugs.

I wonder if they are colder plugs, and if they are if they are just fouled?

Could a bad front o2 sensor screw with the tune? I know the rear is basically just there for catalytic converter efficiency, and is normally disabled by some tuners if the CEL is a problem.

 

Worth the trip; they do all my tuning and I've had fantastic results.

 

u sure all those mods are still on the car or are you just getting that parts list from the ad?

maybe he took some stuff off and kept the same tune. and maybe it was test driven hard.. numerous times..