i just put a new ceramic cat-back and test pipe on my civic. so i took it for a ride down the road. i got on it a little and hit a series of potholes(that i didnt see). i hit them pretty hard. after that my car died and i could get it started but it would idle at like 200rpm and then die no more than 3 seconds later. i checked under the hook and noticed that my fuel press. was at like 52, here my fpr came loose, so i adjusted it back down to like 37 and got the car to start and run. now my vacuum is running at like 15, but it was at 23 before this all happened. the car will run but if you give it throttle it like stumbles upon revving up and it seems like it takes a while for it to rev up. it is also smoking a little,, would the smoke be coming from the new xhaust? anybody have ANY idea what could of happened?

 

It could be a lean stumble.....

However, fuel shouldn't effect the idle rpm unless it is way rich or way lean. You may have a vaccum leak somewhere.

Reset the idle per the service manual. Check the timing. Also reset the ECU.