Hi!
I've recently installed the RRM short intake onto my 2003 Mitsubishi Lancer OZ. After installing, I found that my engine light remains on, and even after I restart the car's main battery(negative battery disconnecting). I am sure that I have bolted every single screws on real tight and that there should be no leakage. However, some of the times the engine light would go off for a few hours or a day, then the next day the light would go back on. I noticed SOME of the times when I start car, the rpm would shoot ups and downs in the low rpm area. Need Help plZ! Thanks!

 

first get the code, that would help

 

I haven't taken my car to mechanics shop to check for the engine light yet, simply because checking it costs money.
Should disconnecting the battery and reseting the car make the engine light turn off? RRM ppl said that I should disconnect, idle for 10 mins, and drive or 20 miles and see. But 20 miles is so much ...

 

If you have an AutoZone or some other parts stores, checking the code is free (I know AutoZone does, not sure about others). Every time you disconnect the battery for a few minutes, the codes should reset. Then after you let it idle for 10 minutes then drive normally for about 10 miles, if the light comes back on, you have a problem, if not then you are OK.

 

Would disconnecting the battery and putting the car back on make the engine light go off? Cause after I reconnect the battery, the engine light comes back on IMMEDIATELY... so I doubt if that idle and 10 miles would help anything... and possibly harm the car instead ...
Sorry for the doubt and Thanks for the help! =]

 

if u disconnect the battery for 10 min the CEL would go off, when you start the car, if something is really wrong the CEL should come back on with in few mins.

 

I just recently had my Engine Performance class and checking codes (among other things) was one of our tests. I'll explain what I know about it.. I hope it helps.

When the car is started it's considered [what's called] a drive cycle. The computer in your car starts telling the fuel injectors and pump to send gasoline into the cylinders and then sends signals to the spark plugs about when to fire in combination with the air flow from the intake.

The computer is constantly checking certain variables, for example: in order to keep the engine running efficiently it checks the signals from the O2 sensors to see if it's sending too much or too little fuel (rich or lean).
When the computer finds something wrong with these variables it takes a snapshot of data, called "Freeze frame data". It saves it in temporary memory and continues to run tests and checks. If the same problem or irregularity in variables is detected the computer will then illuminate the Check engine light, also called Service engine soon, or Malfunction indicator lamp depending on the make of the car or who you're talking to about it.

To sum everything up. The reason your Engine light keeps coming on even after you disconnect the battery is because it keeps detecting a problem. What that problem is you can only find out by getting the code read. Once you have the code you can see what problem the computer is detecting and diagnose from there.

Hope I wasn't too long winded about explaining that. If anyone has any questions about it I'll be happy to explain further with what I know.

 

I got it diagnosed and the code was P0147, which means that the O2 sensor after catalyst was broken or not working well. However, after I finish Diagnosing and getting a price quote(damn expensive), the engine light suddenly went off...and it wasn't on even after a few times of restarting the car. However, I do realize that there is a high pitched sound coming from the back occasionally, though not sure if it was related.

 

That code means o2 sensor bank 1 sensor 3. The Lancer only has 2 sensors though. Not sure how to diagnose this one. If it was sensor 2, I'd say most likely you'd have to replace it. Other than that, your cat converter could be clogged or blown causing the last sensor to read abnormally or make a weird sound from the rear end.

 

It should be bank2 and the after catalyst ( that's what the mechanic told me ) I don't experience any strange sounds, but only the rpm is a bit floaty when i cold start the car.
the lights are off, and its costly. Though i know i must fix it.

 

Would this work for me?
My lights are off now for an unknown reason. I don't wanna waste money when I don't need to...Thanks

 

did the mechanic clear the codes after reading them for you? because that would turn the CEL light off.

thats what they do in my shop...usually tho people are just looking to have the light turned off anyway and don't want to spend any money.

be careful that they are sure it's the sensor that needs to be replaced and not the catalytic converter. if it's your cat and they replace the sensor then the light will just come back on and then you just wasted money on something that wasn't the problem.

i know that there was a recall on this model car for the ECU and Cat as the parameters in the ECU would ruin the cat. as far as i understand all Emissions related parts that fail due to the manufacturer must be replaced by the manufacturer if the car is either 8 years old OR has 80,000 miles on it.