Parts Now Pay Later with
Log In Cart
Log In

Create An Account

Log In Cart
Your Cart Is Empty
Free Shipping Over $199.99

Free Shipping Over $199.99

Orders of $199.99 or more ship free within the continental U.S.

Shipping Policy

Hondata 02-04 RSX Base Automatic ECU Reflash

Images may be for reference only

Hondata 02-04 RSX Base Automatic ECU Reflash

★★★★★ ★★★★★ 6 Reviews
$290.00 & Free Shipping

Reward Points

It pays to shop with K Series Parts and our reward points program! For every $1.00 you spend you earn reward points.

They are easy to earn, just log in to your account when you check out. If you don't have one it is free and easy to setup.

They are easy to use during check out. Click on the "Have Reward Points?" on the shipping and payment selection page.

Reward Point Program Details

You earn 2 points for every $1.00 that you spend.

100 points equal a $1.00 discount.

Maximum discount per order is 5% of the order total.

There is no minimum order total to redeem points.

Points do not apply to shipping or sales tax.

Points are not redeemable for cash.

The point value per dollar, points earned per purchase, and order minimum are subject to change.

Earn 580 reward points. Learn More

Because of the ongoing situation with COVID-19 Hondata is taking at least 2-3 weeks to process ECU's.

Monday-Friday: 9am-4pm MST


The 02-04 RSX K20A3 auto program advances the ignition, alters the cam timing and optimizes the fuel for a cold air intake, adding 5-10 ft lb across the rev range.


  • 7 Peak HP gain depending on the dyno and modifications (results will vary)
  • 5-10 ft lb torque across the rev range
  • Power peak raised 400 rpm from stock.
  • Rev limiter raised to 7300 rpm.
  • Fully dealer compatible - works with all Honda scan tools and equipment.
  • This program was tuned specifically for a cold air intake, as they give the best power gains. The reflash has been tested with race headers and test pipes and both are safe to use.
After you order you will receive two emails; one with full instructions on where and how to send your ECU to Hondata and another with the form that you need to sign and include with your ECU.

You are required to send your ECU to Hondata for this service. This product is final sale.

Not legal for sale or use in California on any pollution controlled motor vehicles. See for state by state emissions requirements.

WARNING: This product may contain chemicals known to the State of California to cause cancer or birth defects.


Brand: Hondata
Part Number: K20A3-A
CARB Approved: No

Vehicle Fitment

Acura RSX
2002 Acura RSX Automatic 2003 Acura RSX Automatic 2004 Acura RSX Automatic

6 Reviews ★★★★★ ★★★★★

★★★★★ ★★★★★
5.00/5.00 Stars out of 6 Reviews
Write a Review
5 Most Recent Read All 6 Reviews
Caleb | September 24th, 2020
Noticeable difference after 5k rpm, car just pulls with little to no loss of power after shifting due to raised rev limiter, 92 octane recommended by hondata but can still run 87, but with 87 car seems to run a little off. With covid 19, hondata took 11 days from receiving to the day they sent it back. Money well spent.
Jason Martinez | August 3rd, 2020
Worth the price, big difference in the car, taking out ecu and immobilizer was super easy to take out and got it back with in 5 days with the tracking #
2002 ECU Reflash
Edgar | June 16th, 2020
Great service. Received it back quick after they reflashed it.
Worth Every Penny
Thomas | July 8th, 2016
This Hondata reflash is by far the best money I have ever spent on the rsx. I completely agree with everyone who says that this is how the rsx should be from the factory. The torque is VERY noticeable; first gear (0-40mph) just flies which makes daily driving and launching from a stop MUCH better. 2nd and 3rd gear also have so much more usable power that freeway pulls are much more enjoyable. Kseriesparts does not disappoint. They give you instructions on how to mail Hondata. It was a very simple process. I mailed my ECU, Key, Immobilizer, and paperwork on tuesday morning and got everything back on thursday. Hondata is very fast with their turnaround. Thank you for the great customer service and product. 110% satisfied, because this reflash, bang for buck, surpassed my expectations. Do not hesitate if you have been looking for more power in your base.
Jordan | May 28th, 2012
Can you ship to Canada?
Read All 6 Reviews