My car was running fine,I installed new headers,new y pipe,when I finished,the car won't start now,I checked fuel pressure and there is none,anybody know what could have went wrong

 

are the keys in the ignition?

 

but seriously a few things could have happened. but more info wpuld be helpful. are you getting any spark? you sure you just dont have a dead battery? no fuel pressure well the obvious would be to say fuel pump went out on you. does the car crank? or are you turning the key and nothing at all happens. need to know what is happening when your turning the key. did you install fresh new o2 sensors?

 

Battery is good,engine is turning over,I gotta check for spark,I used the old 02 sensors

 

dont re use old o2 sensors. i did when i did my headers and two days later my car started misfireing so bad i couldnt go above 20 and had to limp it home. installed bosh 13111's and fired her up, havent had a problem since. check for spark tho o2 sensors might not be it, with headers you should be able to pull a plug , so do that and check to see if there covered in fuel or if they are in bad shape, etc. no fuel pressure is a key concern though look into that fuel pump if your getting spark.