Hi I have a 2005 rx8 and it idles rough at about 820-790 and bogs down to around 500 when you put in gear some times has a p0300 but than it gose away I’ve replaced all plugs wires and coils packs even the crank sensor and maf sensor please help?

 

It’s automatic to if that makes any difference

 

i had my rx8 sitting for about a year, when i finally got it running and unflooded the engine mine did the same.
After replacing the throttle body it was all good again.

in your case with the misfire code though it probably isnt the throttle body.
it could be a long list of things most commonly like:

• Faulty spark plugs or wires
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector(s)
• Burned exhaust valve
• Faulty catalytic converter(s)
• Stuck/blocked EGR valve / passages
• Faulty camshaft position sensor
• Defective computer

did you take off the air intake at all?
a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor could also cause this issue.

 

Think these red ones are shot??

 

I replaced all my injectors now my car won’t start at all???

 

Possible you mixed up the injector plugs? There are 2 beige and 2 yellow, look about the same with grime on them. Double check that.

 

How do I know what one gose to injectors the only wire with anything on it is one with a tan looking tape and the rest don’t have anything

 

Do you have a pic or diagram that shows where each one gose by chance