this season i installed a cutout on my exhaust setup and it seems to cause some major issues. I'm curious if this is common as i've never ran one on a car before. particularly during idling or low cruising speeds to the point that over the summer the car completely cutout as if it were out of gas after running in a cruise with the cutout open. Has this happened to anyone else?

 

where is the cutout placed in relation to the oxygen sensors? are you still running a gm ecu?

 

Was just about to ask whether your O2 sensor was before or after the cut out. I wonder if you burned a valve? Although I don't really see that being very likely to happen.