DallasAp1

Ive been reading about this ecu swap people have done with there 00-01 ap1's to the 02-03 and saying it makes it a smoother/slightly more peppy down low.
the biggest thread of info i found was this one https://www.s2ki.com/forums/index.ph...ic=282571&st=0 but that still didnt answer everything for me. One thing i wanted to know is well it says you have to get your key reprogrammed because of the chip in it, and i was wondering what about the key fab is that still gonna unlock my doors too? sorry if thats a dumb question. also i was wondering how many people were satisfied off of this upgrade and did you think it was worth it? im pretty much happy with my car and the reason this appeals to me would be making it easier to drive around town and its not like it costs a fortune.
And one last question since the A/F of the 02-03 is going to be more lean than my stock ECU will my car run too lean since mine has a k&n intake along with a dual exhuast + berk hi flow cat? or will those mods not be enough to alter it and the ecu swap will not risk me harming my car?

DallasAp1

can someone atleast answer my question will it be ok to do this ecu swap if i have aftermarket intake and exhaust?

S2KIrishman

you dont think people with 02's and 03's put exhausts and intakes on there cars? it'll be fine

DallasAp1

thanks for the reply, i was just not sure i was told the 00-01 was richer so putting a few bolt ons would not harm without a tune and the newer s2k's(post 00-01) a tune was recommended with bolt on but i wasn't sure if it was needed just trying to be safe rather than sorry

s2ka

I did this to my 00 earlier this year. I bought a used 02-03 ecu for $70, took it to the dealer, told them I wanted it installed and the keys programmed to it. Some dealers require you to bring your proof of ownership (pink slip etc). It took them a couple hours which included cutting a spare key (my car only came with one key and I wanted a spare). The keys have to be matched to the ecu. I don't think the fobs need to be reprogrammed but I had them make sure they worked at the same time.

I'm guessing some dealers are more savvy to this procedure than others. If you have multiple dealers nearby you might call ahead and see if they sound like they've done it before. Get a price quote while you're at it. Mine was something like 1 hour of labor plus $20 for the key. Total was around $120, I provided the ecu and extra fob.

The benefit of the ecu swap can be felt. It's not a giant change, but it feels more responsive. I had an 03 car for a long time so I know what it was supposed to feel like. My 00 never felt as good as my 03 until I swapped the ecu. Now it feels great just like the 03. For around $200 I think it was a worthwhile mod.

I put 4.44 gears in both cars, huge difference, much bigger gains than the ecu swap and highly recommended for AP1 cars.

DallasAp1

thank you for feed back much appreciated

s2000Junky

I don't think its worth the hassle or money. I think A better option for the same cost would be to swap in a larger TB like one from SOS. This is going to give you a noticeable throttle response improvement and about 5whp across the rpm range NA and over double that FI. When you start getting into breathing bolt on modifications on this car, the earlier 00-01 richer mapped ecu's actually start to benefit you, especially if you ever do a F22 swap in the future as these require more fuel to run safe.

phaeton

I just picked up an '03 ecu to swap into my '00 AP1. Question - I just moved and only have one of my keys with me. If I take the ECU (I have the VIN) and the key I have to the dealership, can I take my second key to be reprogrammed at a later date? Any issue with that plan?

s2ka

You can do it at any time.

schhim

I swapped to an 02-03 ECU in my '00 and it's a very subtle difference. To me, it feels a bit better at lower revs. And if you're hoping for F/E gains, there really isn't any.