First, cook the macaroni in salted water until al dente. Drain the pasta and run it under cold water to stop the cooking process.
Now, add the cooked and fully drained/dried macaroni to a large bowl and add the chopped onion, bell peppers, celery and relish.
Then season it with salt, pepper, garlic powder and onion powder and mix everything together until it’s evenly combined.
Now, in a separate bowl, mix together the mayonnaise, yellow mustard, vinegar and sugar. Lightly season it with salt and pepper then pour it over the macaroni. Mix to combine.
PLEASE NOTE: Sometimes, if the pasta isn't dried completely it can absorb some of the sauce and dry it out. If this happens, feel free to make another batch or half batch of the sauce to add to the macaroni. Some may want to do this anyway if they prefer a creamier macaroni salad texture.
Then, cover it and place it into the fridge for a couple hours or overnight.
Finally, give it one more big stir once you’re ready to serve and enjoy!