modifications > Cobb ECU Flash

Why did you flash the ECU in your RS?

Because my tuner said so! The pictures below show the steps that I took to reflash the factory Focus RS ECU with an off-the-shelf (OTS) Cobb tune for 93 octane using their AccessPort device. In the next week or so when the rest of my W400 kit comes in and I install it, I will reach out to Adam at Tune+ to read my datalogs and create a custom mail order tune for my RS. Then I can lay the smack down at the 1/4 mile!

Date Completed:



- Cobb AccessPort with Accessories (provided with Tune+ W400 kit)
- Sweet Tea (optional)


- Battery Charger
- Your brain
*A friend for moral support is always optional.


1. Install takes 15 minutes or so. Turn off your lights, radio, air conditioning, etc. to minimize battery drain.
2. I highly recommend connecting a battery charger while you do this. You could kill your ECU if the battery goes dead in the middle of this flashing operation.
3. Continue at your own risk. This could potentially void your warranty on the Focus RS. Some dealers are mod friendly, but tread lightly.
4. Pictures are in sequence from start to finish with the Accessport reflash.
5. Take note of the 2 error messages that come up on the dash (pictures 26-29).
6. I removed the accelerator pedal plastic wrap after I noticed it. WHAT A NOOB!
7. I chose the 93 octane OTS tune map to start with. Custom Tune+ mail order tuning coming soon!
8. I didn't show all the steps to setup the AccessPort real time gauges because there are tons to choose from!
9. I will order a windshield suction cup mount for the AccessPort. Don't trust the adhesive tape stock mount.
10. Somewhat reversible back to stock. Although the stock ECU map can be replaced and the Accessport can be undocked, any dealer will know that you flashed the ECU.