It sounds like it's coming from the exhuast.

I want to change the o2 sensor, I have 48,000 miles anyways, so it wouldn't have hurt and maybe fixed the problem. So I called Mitsu and they wanted $278!! That is expensive. Went to discount auto parts and they wanted $328!! We got some damn expensive O2 sensors! My other car is only $18 for it. Ridiculous. But anyways, when I get home, I will reset my ECU and maybe look at the spark plugs.

Also, I don't have the piggy installed, Ia waiting for my new on from RRM.

 

Damn, my car sucks. Still doing it. Probably take it to a mechanic this week.

 

I'm having the same problem....I think it has something to do with the piggyback. Everything is soldered on it but dont know what the problem is. Does any one know what happenes to the piggyback if you disconnect the battery? Will it remember everything or does it have to learn somethings again?

 

No I don't have the piggyback installed. I took it out and returned it to RRM and got a new one but haven't installed the new one.

I don't think this was from the piggyback since after I took it out this tarted happening about 2-3 weeks after. Hopefully...

But if I can, I will be taking my car to a mechanic sometime this week.

 

If you can, update us on this problem when you take it there.

 

ok

 

my buddy had the same problem with his lancer. we found out the local mom&pop oil change center put an extra quart of oil. we drained it, and car is running perfect again. not sure if that helped or not, but i guess point being check everything.

 

I'll try an oil change then...

 

Changed oil... still doing it.

I went to Advanced Auto Parts to get a code for CEL and they said they don't do it anymore. So I am going to Autozone tomorrow to get it.

I have a CEL for my header, can the reader read 2 codes if 2 things are wrong?

Also if I have a problem with my ECU, would a CEL come on and be able to get a code from that?

 

i had the same problem and drove me nuts for about a month. truned out my coil pack was bad ad making the number 4 cylinder misfire. it took about 2 weeks of driving it around for the code to throw. replaced it with a new one and never had the problem again.

 

I have had that prob for a couple of weeks. I took it into Mitsubishi and they said it was normal (yeah right). They said it was the coil packs adjusting. I can'[t tell ya what it might truely be, but I've also tried everything. But the fact of the matter is it is also driving me nuts!

 

So you replaced the coil pack on the 4th cylinder? I think that is what I will do if the O2 sensor I got won't fix it. I bought the O2 sensor from someone on here and should receive it today.

 

I really don't think the O2 sensor is the problem... because by now you'd have seen a CEL.
If it IS a coilpack, let us know- and tell us how much they cost. Did you ever get it on a code reader?

How many miles on your car?

 

Well I have a CEL code because of my header so I don't know if it was from whatever.
I have 49k miles.

And I figured out the problem!!

The spark plugs.. at first I didn't think it was them because I recently changed them and no problem. I put Autolite plugs in and it didn't start messin up till maybe 1k miles after that. Well I put in NGK VPower plugs last night.. like $5 a piece, they were recommended for my car or something. Now it runs great!

 

i have the same problem i think!........but mine is at very low rpm's actually at a stop and accelration for like 300rpm's but its more like a gargling sound like fuel not compusting right are like to much fuel....i have no mods what do you guys think might be the problem!?????