I suspect variations of this question have been asked in the past, but I ran a search and didn’t find anything with anyone using the downstream CEL eliminator contraptions to eliminate the Check engine light coming on. Was wondering if any of the more modded users here have used them, and if so what side-effects (if any) were noticed. The upstream ones are in my opinion, the more important ones and you dont want to mess with the input the ECU gets from them since that is directly affecting the air/fuel mix. Unless things have changed in ECU inputs, the downstreams were mostly just for emissions purposes and gauging how effective your cat converters were doing their job. I have seen many people mentioning they were running gutted converters or straight piping after the headers. I’m referring to Gen2 models if there is any difference than the Gen1. So long way of asking, those with gutted converters, are here any adverse side-effects to your performance?