On eBay, you often come across offers for chips that supposedly boost performance, but they cost only a fraction of what established tuning companies charge for their chips.
I understand that chips purchased on eBay typically don't have an approval certificate (ABE). However, these sellers often advertise that they are copies of the original tuning software from well-known tuners.
That probably applies to tuning boxes as well, right?
Has anyone had any experience with these 'cheap' aftermarket tuning parts?