I had a really big problem, I'm posting the the problem and the resolution for anyone who has experienced this. My 89 325 IC had a really bad jerking, just like bogging when you have bad points or you car is outta timming or maybe even when you are running outa gas, well anyways I got the solution. I spent about $250.00 trying to guess what the hell was wrong with my car, I put on another CAT. and paid for a diagnostic btu he guy couldnt give me a reason. I took of the "Crank Sensor" and it was dirtier that shit, I cleaned it and my car runs like a charm... no stalling, jerking or bigginn. If anyone has ever had this problem dont guess go straight tothe sensor and clean it up and it might just fix that issue. Well happy driving the "Ultimate Driving Machine".