How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask OnlineHelp Your Own Question
OnlineHelp, Mechanic
Category: Car
Satisfied Customers: 3423
Experience:  Mechanic
Type Your Car Question Here...
OnlineHelp is online now
A new question is answered every 9 seconds

2000 Mazda B2500: high idle..scan tool..the egr monitor has not run it

Resolved Question:

I have a 2000 Mazda B2500 and I am having a problem with high idle. I have a scan tool and it shows code p1506 and the egr monitor has not run it's test.   Can you give me any explanation ?
Submitted: 7 years ago.
Category: Car
Expert:  OnlineHelp replied 7 years ago.
Hello and thank you for choosing JUst Answer.

Actually that is a general code definition for p1506. The mazda definition is different.
P1506 indicates that the engine is idling at too high an RPM and the engine control computer is unable to bring the idle down to specifications.

I would suggest that you first check for vacuum leaks. Common vacuum leaks are around the intake manifold and throttle body. Turn the car on and spray those areas with some brake fluid, if the idle goes up/down during the spray that would mean there is a vacuum leak.

If you do not find a vacuum leak you need to check the idle air contorl valve. It is mounted on the thorttle body and it regulates the idle. Here is how it looks:
Customer: replied 7 years ago.
As I have already stated , I have replaced the iac valve and checked for vacuum leaks. Any other suggestions?
Expert:  OnlineHelp replied 7 years ago.
Have you check the fuel pressure?

You have done all the common trouble shooting associated with the issue. You may want to consider putting the car on live-data to monitor all the sensor outputs and check the air/fuel ratio on the car. This is a very precise test that would show if anything is out of range.
OnlineHelp and other Car Specialists are ready to help you