I love the idea and concept of this filter and I'm sure it will do amazing things for my engine but I'm giving it 4 stars just because of fitment issues. You can't just throw it in a 1999 5.9 cummins. It won't fit. I had to drain the refrigerant and pull the compressor lines and bend them a little just so I could fit the filter in. After that, I could get the filter in and out but still with some difficulty. If you don't have access to a AC machine, youre probably going to have to end up removing the whole compressor just to get the filter in. You can't bend the lines while they're attached to the compressor. You'll break the seal on the lines and get refrigerant everywhere. If anyone else had the same problem and found a different work around please let me know what you did because I really want to keep using this filter
