Service engine light 03 eclipse

[korben_dallas]

2003 eclipse GS. ok my engine light came on and i took it to the dealer they said i had a o2 sensor manfunction. got it replaced but my car is still running shitty. the dealer is the one who replaced it i have 59k on car. the warrenty is up at 60k. my car make like a jerky kind of motion when i take off and feels like it is going to die. i have to have my rpms kind of high when i take off. anyone have any idea's what might be the propblem. my car is manual trans. please help???

[perna00]

it sounds like you have a vaccum leak. it will also cause your car to run lean which will throw an o2 sensor code cause of how much air the o2 sensor is reading. the leak is going to be somewhere between where the intake bolts to the head and the mass air flow sensor. let me bet, the car jerks really hard at low rpms then smooths out after it gets into higher rpms?

[korben_dallas]

that exacatly what it is doing. once i get in the higer rpms it turns out ok. so what should i do to fix it and about how much does this cost???? is it bad for my car to be running it like this? because the dealership i go to is about 1 1/2 hours away? or do you think i could probably fix it my self???

[perna00]

your car is getting too much air through the vacumm leak and it is throwing off your fuel/air ratio. the car in turns try to cut the amount of air coming through the engine, but it only cuts it too much since it's not a computer controlled leak. it keeps repeating the process giving you the surges. when ever you are at higher rpms the small leak doesn't make that bid of difference so you don't notice it that much. just check for everywhere the tubing meets other parts and make sure the intake is snug to the engine

[BackseatJesus]

(2003 GS)
My problem comes from a different but very similar source. I've got the same power loss problem which can be described as "putting" up until 3,000 RPM's... you cannot floor it in low RPM or else it bogs down and feels as if the car will die out. We had put in an AEM intake and after that the Light came on and we've been having problems. I know the fuel/air ratio is off, but when put on the datalogger it threw out the "bad spark plug" code. and so i was wondering what to do, adjust the choke...Check the plugs, distributor, vaccuum hoses? What should i do? Oh and i was wondering if this would affect top speed, cuz we're topping out at 125...

[eclipsed4utoo]

adjust the choke?? anyway if you have an automatic then i think your top speed is about 125

[BackseatJesus]

i didnt mean choke, but more-so the throttle valve, anyway any ideas on how to fix this problem? And yeah it's the sporttronic so no hopes for anything higher until enough money rolls around to increase the power...