I recently bought my first GN about a month ago. I has a TT 5.7 chip with 60lb injectors bought as a package. From the receipt I got from the owner it was purchased back in 2016. Car runs and drives great my question is. He had a the cat put back on the car due to where he lived. Would there be any difference in the chip from 2016 to 2018? If I cut the cat back off will I need a new chip? Car showing leans out at WOT on gauge but not seeing Knock retard and Scan Master, could that happen due to putting cat back on? Basically just need to know if I should buy a new Chip or not. Thanks for the help