Replaced iac valve, still get p1506 code and check engine light.

Question

I have replaced the IAC valve but still get the 1506 code and the check engine light remains on. Disconnected the battery to try to reset codes, but same result. Any ideas?

Answer 1

P1506 IAC  (overspeed)

Vacuum leak are common cause for this code condition, Some of these causes are from the EGR or PCV hose or PCV itself, You can use a brake cleaner or carburetor cleaner and spray along suspected area and note any RPM changes, Sometimes this code is a challenge where the RPM is high and no vacuum leaks found, if this is the case try this, remove the IAC valve, plug the IAC opening if the idle still remains high you have vacuum leak if you choose this method you would be able to hear the vacuum leak, by the way the best plugged is the palm of your hand.