Hello every1 I have a buddy that has a 97 EX 5 speed that was heading to work in a hurry.He hit a basement size chuckhole bottomed out. then his civic got quieter and started to loose power (still ran). It was running like a top before he hit the hole. It is throwing 4 cel codes for #4 cyd misfiring,#3 cyd misfirng,multiple cyd misfiring. We took the timing cover off and made sure no jumped timing belt happened. found out that the heat shield for exhaust cut into (not thru) the 2 nd o2 sensor on cat conv.when it is running it smells like 2 cycle oil sort of.We have run out of ideas except the Cat could have got clogged. any input on what could be wrong will help alot. Thanks again