My civic dx when at idle bogs down and the revs back up contiously like when I'm at a light with the clutch in or just in neutral, could be my intake(96' aerospeed frontmount)sucking in to much air, or just not maid correctly for my year car, it has been doing this for a while I replace the idle air control and the throttle position sensor and it hasn't fixed it yet.

Any Ideas????????

 

check your vaccum lines, and make sure you don't have air in the coolant lines... top off your coolant too.

 

first off that intake is crappy

ManInCamo is exactly right. Check the vacuum lines to make sure one isn't cracked or off and make sure your coolant is full. Bubbles in the coolant lines/channels have been known to effect idle.

 

Vacuum leak:

Check vacuum lines, IACV o-rings, TB gasket, intake manifold gasket.

To check gaskets, simply spray starting fluid onto the gasket(s) at idle and see if the motor responds.