I have a somewhat small question. I have both a 03 Oz 5 speed and a 04 ES auto. Me and my Fiance are wanting to swap the transmissions between the two. She bought the 5 speed for me to drive and she could drive my 04 auto. She likes the 03 body better and I miss my 04 body. I've been doing my research and am looking into having them switched over. I already know everything I need is there. My questions come down to two things.

1. Since the 04 doesn't have a fuel return line, is that going to affect the ecu when I swap it over to the 03 with a return line?

2. What do I have to do to use the Cruise control on the 03 when I swap the 04 auto and ecu over? Does it need a new computer?

3. Is there any wiring differences between year models, not transmissions?

Thanks for any help.

 

your going to need to transfer the ECU also

 

I forgot to put that down. Will the 04 ECU work with a return line and will the 03 work with returnless?

 

you can swap the entire return fuel line assembly onto the 04 haha

 

Thanks, that is true. I would rather swap over the line. Would the ecu work even if I didn't swap over the line. Also, what all do I need to do to use the cruise control on the 03? do I need a new harness and ecu?

 

idk about the cruise control, you'll have to swap the intake manifold and the throttle body and whatever is needed

 

I would say just switch engines and trannys. Cause you would need to swap the clutch pedal and all that and linkage. Swapping originals with originals would save you less work in the long run

 

I've considered doing that. The only reason I don't want to do that is the 04 is younger and feels like it runs somewhat better. It would save me time. I'm also thinking it would probably save me time just to buy an wiring harness for both and new ecus for both.

 

I think the best ideal would be swap out all parts(engine/tranny). I would say when switching you would need the center console also for the shifter boot and swapping that out wouldn't be a problem i don't think. There is also the gauge cluster that the ES doesn't have. Thats pretty much all i can think of.

 

I figure I have just about everything I need. I know the transmissions are the same from 02-06 weither it be auto or manual. The mounts, master cylinder, pedals, shifter, cables, and about everything other than the wiring and ecu haven't changed any over the year models. I just figured since the 03 had cruise and I don't need it in the 04, I'd rather my fiance be able to use it instead of it going to waste. I figure I just need to save up and get the proper wiring harnesses and ecu's for each and not risk running into wiring issues. I prefer to leave it intact instead of cutting and rewiring.