i have a 99 civic ex stock motor, d16y8, it was running fine untill 2 days after i installed a dc sport headers (some scrapes on the bottom) it started acting up...
the check engine light was on reading a bad o2 sensor...

when it is a cold start, it runs fine, but if i turn it off and restart it... it feels like it is about to die.., it idles a little lower than usual like around 600rpm, and when i drive it, it jerks like pressure building up then fully releasing.... after a couple mins the idle jumps back to normal and it does the same again everytime i turn it off an start it up from a warm start...

any ideas on what i may be.. please let me know.. thanks

i already cleaned my filter, intake arm, and throtle body, the dude from kragen told me it may be a bad o2, or another sensor from the intake arm (which i cleaned also) but it still acts the same...

 

So you get a check engine light that says its the o2 sensor?

 

yup

 

So replace it?