DHM Performance ECU Flash for the 2022+ Honda Grom / Monkey

DH Motoring

Regular price $159.00

Shipping calculated at checkout.

Customer Reviews

Based on 178 reviews
James Gammons
22+ grom ecu(exhaust only)

Definitely has more throttle response. Doesn't lose as much speed on inclines. Might be worth it more if I were to add an intake, but as far as just exhaust, it's definitely an improvement.

Sam Notarpippo

Only placed my order a few days ago already got my items, talk about fast shipping!! Will be installing tomarrow after the weather clears, got the stage 1flash with tst worx cover an decha stealth tube!! Heard so much about these guys. Had to do it can't wait for the beast to unleash!!!

Vincent E.
If you're on the fence, buy it!

The tune made the Grom come to life. I went with the ECU tune for TST Works Airbox cover and Zoom Loop exhaust and it made such a difference going uphill maintaining speed. I'll do the s1 cam and retune soon but this is fun for now! Waited too many years to get an ECU tune but I'm glad I waited for at least the 2022 model to get it for the 5spd. Thank you for the quick turn around on the order.

Randy Chiu

Service is perfect, prompt shipping, smooth transaction, but not sure if I did the reset right, don't feel the performance differences....

Brandon Phillips
Best thing ever

First off super fast shipping. Ordered Friday at lunch at it Monday when I got home from work. I did the stage 1 tune with my intake and Yoshimura exhaust made a huge difference. Throttle is crisp and clean.

After months of development, we're now offering ECU flashes for the 2022 Honda Grom and Monkey!

Two ways to order: Select to send your ECU in and we will flash it and send it back OR Select to purchase a new core preflashed ECU.
Does not work on European, Japanese or Korean spec bikes.    
The 2022 engine doesn't run as lean in the lower RPM as the previous generation, but still runs lean at higher RPM once an intake and exhaust are added. Honda was also very conservative when mapping the new bike, and has left a bit of power and throttle response on the table. As seen in the dyno graphs, we've been able to pick up quite a bit of mid range power and we've also smoothened out the awkward power hiccups that the stock mapping had. 
The DHM ECU Flash modifies the following:
  • Fuel mapping - we remap the entire fuel table to help your bike run safer while also making more power than the factory mapping. We can maintain factory fuel economy at part throttle while also making sure the bike runs safely and effectively under load. Fuel mapping is essential to keeping engine temps down.
  • Ignition timing - we modify all spark angle maps to increase throttle response and power while keeping temps down. This can also help with fuel economy at part throttle, while allowing gains across the board when under load. We've altered the timing to eliminate the factory power dip around the 5,000rpm mark.
  • SOI - Injection timing is modified to make sure that fuel is delivered at the most precise moment to increase efficiency and power. 
  • EOT Tables - We alter engine operating temperature tables to make sure the ECU compensates for high engine temps. This failsafe helps prevent engine damage when extreme temperatures occur.
  • Optional - Tip sensor delete and Cold start delete
Map Options:

  • Exhaust Only: For bikes that are bone stock other than an aftermarket exhaust system
  • Stage 1: For bikes that have an aftermarket intake and exhaust installed
  • Stage 2: For bikes that have an intake, exhaust, and aftermarket camshaft installed 
  • Stage 3: For bikes that have intake, exhaust, camshaft and our DHM piston installed
  • DHM 149cc Big Bore: For bikes that have intake, exhaust, the DHM 149cc kit, DHM S1 camshaft, and Honda PCX150 fuel injector (16450-KZY-701)
We have maps for nearly every combination of intake, exhaust, and cam, and are currently updating our library daily. If you don't see your mods listed, feel free to inquire, we may just have a setup for you. 
We currently have maps for the following exhausts: Yoshimura single, Yoshimura Dual, Hindle, Vance&Hines, Anodized Racing (Amazon), Over High mount, Toce, and the Zoom loop and Brute. 
We have maps to work with the following intakes: Chimera, MNNTHBX, TST Worx Cover, Airbox mod, and Dinger.
We can map for the following cams: DHM S1 / CJR S2, DCR
We have maps for the following pistons: DHM Stock Bore
Our S1 cam for the 2022 model can be found HERE.

Our stock bore high compression piston can be found HERE
Our big bore kit can be found HERE.

If you are looking for packages that include s cam and/or piston, you can find those here:

Stage 2: https://www.dhmotoring.com/products/jc92campackage

Stage 3: https://www.dhmotoring.com/products/jc92stage3
***After checkout, you will receive an email confirmation that will include shipping instructions, as well as a link to an online form that will ask for your specific mods.***



  • Orange: Bone Stock
  • Green: Stock with Yoshimura Exhaust
  • Purple: Yoshimura Exhaust and DHM Flashed ECU
  • Red: Yoshimura Exhaust, Intake and DHM Flashed ECU

  • Blue: Stock 
  • Green: Chimera Intake, Yoshimura Exhaust, DHM S1 Camshaft, DHM Tune