: Originally designed to work with a physical Avenger Box hardware security dongle, though various "cracked" versions (which bypass the need for a physical box) circulate in technician communities.
Solution: You likely missed overwriting a file or have a conflicting old mod. Delete the data folder (after backing up) and reinstall the game, then re-apply the mod strictly.
Requires a specific sequence of installation to avoid crashes. Final Thoughts Xtm Avengers Main 1.8
Safety first: Let the vehicle cool completely. Spray penetrating oil on the three exhaust hanger rubbers and the two bolts connecting the stock exhaust to the downpipe.
Remove the stock system: Unbolt the two 15mm nuts from the downpipe flange. Use hanger pliers to pop the rubber mounts off the metal hanger rods. Move the stock muffler out from under the car.
Dry fit the XTM Avengers Main 1.8: Slide the mid-pipe onto the downpipe. Do not tighten yet. Hang the muffler section on the rear rubber hangers.
Connect the clamps: Slide the included 1.8-inch band clamps over the slip joints. Align the tips so they are centered in the bumper cutout.
Tighten: Starting from the front (downpipe) and moving back, torque the clamps to 35 lb-ft. Tighten the hanger bolts.
Check clearance: Start the car. Check for leaks by feeling for puffs of air or listening for "chuffing" sounds. Re-adjust as needed.