I am getting a P1506 error code?

RDELAUNE

MEMBER
1998 MAZDA 626
2.0L
4 CYL
2WD
MANUAL
250,000 MILES

I am getting a P1506 error code. The following have been cleaned: MAF, Throttle Body, IAC, EGR. The respective gaskets have been replaced. After cleaning the parts, the engine was idle "hunting", about 250RPM, so I adjusted the idle. The "hunting" is now very minimal, really not noticeable. I am still getting the P1506 error code. Any ideas? Does it sound like I need to continue adjusting the idle? Thank you.

2 Replies

HMAC300

MECHANIC
48,601 POSTS

E pic for causes but also check for a vacuum leak and air leak between air cleaner and throttle body.

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Saturday, January 24th, 2015 AT 6:29 AM

KEN L

MASTER CERTIFIED MECHANIC
47,639 POSTS

The error code P1506 on a 1998 Mazda 626 indicates an issue with the Idle Air Control (IAC) system, specifically an "Idle Air Control Overspeed Error." So this means the IAC is stuck, I would remove it and clean it here is a guide to help and the location of the IAC in the images below.

https://www.2carpros.com/articles/idle-air-control-valve-service

If cleaning does not work replace the valve. It could be the idle speed adjustment as well. Check out the images (below). Please let us know what happens.

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