Claas V8 OM502 Tier4A Engine Reflash
From $1,995.00
Couldn't load pickup availability
Want next day delivery? Be quick!
Shop safely
Secure your shopping experience with various safe and trusted payment methods.
Claas V8 OM502 DPF & EGR Reflash
Built for Tier 4A Lexion combines and Jaguar forage harvesters running the Mercedes-Benz OM502 V8. Flash the ECM yourself with our Reflash Master handheld, or send it in and we bench flash it for you. Either way the DPF and EGR stop costing you harvest time. We ship all across the US and Canada.
Reflash Master
Flash it on the machineWhat's included
Prefer we do it? Bench flash
Next-day turnaroundPick the bench flash option and we email shipping and customs details after you order. Pull the ECM, send it to us, and we program it and ship it back for you to plug in again.
After the tune
Claas machines it fits
Tier 4A Claas machines powered by the Mercedes-Benz OM502 V8.
Running a different engine or tier? Email us your data plate photo and we will point you to the right product.
Why delete the DPF and EGR on a Claas OM502?
Diesel particulate filter
A V8 pulling a full header or chopping corn all day fills its filter quickly, and every regen dumps fuel into the exhaust to burn the soot off. When a regen gets cut short the filter keeps loading until the machine derates in the field. Hollowing out or piping the canister ends regens and opens up the exhaust.
Exhaust gas recirculation
The OM502 routes some of its exhaust back into the intake to cool combustion, and that gas carries soot into the valve and cooler. Over time the valve sticks, the cooler clogs and fault codes follow. With the EGR shut off in the file and the port blocked, the intake only takes in clean air.
Frequently asked questions
Q1Which Claas machines does this reflash cover?+
Lexion 760, 770 and 780 combines and Jaguar 940, 950 and 960 forage harvesters with the Mercedes-Benz OM502 V8 at Tier 4A. Send your data plate photo and we will confirm the fit before you order.
Q2Do I need to send my ECM in?+
Not if you choose the Reflash Master option. The handheld and its specialty cable flash the ECM while it stays wired into the machine. If you would rather not do it yourself, pick bench flash and ship the ECM to us.
Q3How long does a bench flash take?+
We flash it and ship it back the next business day after it arrives, so you only wait on shipping. After you order we email the shipping and customs details.
Q4What happens to the DPF?+
The diesel particulate filter has to be hollowed out or replaced with a straight pipe. Once the reflash is on, the machine no longer monitors it or tries to regen.
Q5Should I block off the EGR?+
Yes. The reflash shuts the EGR off in software, and we recommend a block-off plate as a fail-safe so no exhaust can make its way back into the intake.
Q6Does this add horsepower?+
No. This reflash is for emissions removal only, and the engine stays at its factory rating.
Q7What warranty comes with it?+
Every OM502 reflash includes a 1 year software warranty.
Q8Disclaimer+
Off-road agricultural use only. Not for machines registered for highway use. Buyers are responsible for knowing their state or provincial laws.
Why Reimer Tuning
We are a Canadian company that has tuned ag equipment since 2014. You can flash your OM502 yourself or send it to our bench, and either way you get a 1 year software warranty and techs who answer the phone during harvest.
Emailing us? Attach a photo of your engine data plate.
Off-road use only. Not for machines registered for highway use. Buyers are responsible for knowing their provincial or state legislation. All sales final.

Shopping Safely
At our Shopify store, we prioritize your safety and security. Here's how we ensure a secure shopping experience:
1. Secure Transactions: We use advanced encryption to protect your personal and payment information, ensuring it is safely transmitted and safeguarded.
2. Trusted Payment Gateways: Our store integrates with trusted payment gateways, ensuring your transactions are processed securely and efficiently.
3. Data Privacy: Your privacy is our top priority. We follow strict data protection policies to keep your personal information confidential and secure.
4. Secure Platform: Shopify provides robust security features and continuous monitoring against vulnerabilities, ensuring a safe shopping environment.
5. Verified Merchants: We are a verified merchant on Shopify, committed to providing authentic and high-quality products.
6. Transparent Policies: Our clear return, refund, and shipping policies provide peace of mind, knowing we stand behind our products.
7. Customer Support: Our dedicated customer support team is ready to assist with any concerns or questions you may have.
Shop confidently at our Shopify store, where your safety and satisfaction are our top priorities.
$1,995.00