ok i have a 2004 civic dx 5spd with a bad ecu.the question is will a 2003 civic lx 5spd ecu work with my car? trying to figure it out before i purchase iv'e searched but i can't find nothing out .thanks

 

It should function the same, but they do have different part numbers:

-2004 DX KA5MT: 37820-PLM-A15
-2003 LX KA5MT: 37820-PLM-405

 

I think like toyomatt says all should be fine going from an LX to a DX, all within 03-05 years. Manual vs. auto transmission might be more important. Still, I would aim for a DX ECU with your car's tranny. Maybe try http://www.car-part.com/ . With a simple search, it will list many junkyards that sell this ECU for around $200. I used this site a couple years ago, calling a number of the junkyards it spewed out. All seemed legitimate. I know another person who used it, from search to purchase, and is pleased.

 

thanks for your help i just can't seem to find a dx ecu.but im going to search car-parts.com and see .

 

i think you might have issues because the 2004-2005 models use an A/F sensor while the 01-03 uses regular oxygen sensors?

 

i just bought a 04 civic dx ecu, so i should be all set once i reflash the keys to the ecu.thanks

 

Please elaborate on what you mean here. Oxygen sensors measure fuel levels in exhaust gasses, so I guess I don't see how you would distinguish between that and an "A/F sensor".

 

He's referring to a LAF... Linear Air Fuel sensor also known as a wideband o2 sensor. Honda just uses the LAF acronym everywhere in their documentation.

I don't remember seeing a LAF on my sisters 2005 Civic Reverb (dx w/stereo + bodykit).
theineffable are you positive about that? (I don't want to argue, I'm really not 100% sure).

juni413 -- good to hear you found one. Let us know how you make out with it.

 

Well, I do not recall reading about an LAF ever being implemented on a D-series from the factory. But, I could be wrong.

 

going to honda tomorrow to reflash the keys to the new ecu.i connected the code reader and it say's pass no codes .wish me luck..

 

did you get it flashed? All good? I'm in this boat and wanted to know