My car idles rough and when i rev it up it goes to 3k rpms and hesitates revs back down then goes back up whole the peddle is still down. Also while driving it, it has no power it seems and bogs down. Sometimes it wont go faster than 30 mph and makes terrible noises and when I'm on the highway and go WOT the rpms go up slowly and stops at 4k rpms and then goes on up to 5k or 5.5 slowly then finally shifts. So far I have replaced the TPS because I though it had something to do with that. It has been like this for the past 4 months and it all started after I slid around a turn and hit a pot hole. the car is an automatic. sorry if it doesnt make sense im new to this.

 

im assuming its a 96z28. have it scanned for trouble codes. call the local autozone and see if they can do it for u. if its running like u say then it should be storing something. could check the fuel pressure if u have access to a tester. have u had the service engine light come on? let us know what the codes are and we can go from there.

 

Look under the car and check to see if your exhaust is crushed anywhere. The pothole could have flattened a pipe, making the engine unable to breathe (exhale).

 

it throws the crank shaft positioning sensors and O2 sensors. it has no cats on at all. but it has threw those codes since i bought it and drove just fine up until i hit that pot hole.

 

im gona say check for a short or lose wire. check the 02s wires and maybe take em out and have a look at em. u are supposed to change em once in a great while. look all the wireing over u can see and look for lose plugins. hate to say it but u may have jolted the last few miles out of the opti. how old is the opti?

 

So...you don't have a crushed exhaust? You didn't say yay or nay. If the exhaust system is restricted, exhaust gases won't be flowing past the oxy sensors like it should be, which can trip an oxy sensor code, among other problems it can cause.

 

i checked the exahaust, it lookes fine all the way back. i wish i could show you guys whats it doing, i cant really explain. i was driving it today and it randomly backfired going down the road. it really runs like crap. ill try to take a video of it, the quality wont be great but ill try to keep it on the rpms.

 

i know the opti is at least a year old. i have never replaced it. im thinking it probably does need a change.

 

yah good luck changing optis suck

 

dont want to throw you that way but..opti can cause all kinds of issues and can get "jarred into oblivion"must've been a heck of a pot hole!!lol.and as crabby said could have just jarred something(ground,connection)loose somewhere.best to check all free checks first and i mean coil/icm grounds/connections,all plugs to sensors,o-2's etc.any codes being thrown?