So if I get a tune for my catless dp everything will be fine? How will they delete the cat diagnostics test? If they dont it'll dump full all the time to keep checking for a cat on top of a tune which would not be a good tune since you wouldn't have a locked in afr or even consistent ltft & stft tables. So tuning is not the key it'll help but the cat diagnostics test is what we need to eliminate before we can even rule anything out tune or etc