Hi everyone I am new to honda and to here. So I am working on a 2004 honda crv 2.4l for a friend. The timing chain was replaced at 140000 miles and it have 141000 on it now was getting a map code so replaced map sensor then a iac code popped up so replaced the iac now I am getting a p0300 code with p0301 and p0302 and sometimes either p0303 or p0304 but not all the time I have hooked up a scan tool an the advance idle rpm is all over the place and temp at idle is over 200 degrees. My question is what is going on and how do I fix it with out throwing a bunch of unnecessary parts at it? Thanks in advance.

 

Just throwing it out there, but have you looked at the plug stems that go down to the plugs?
Ever since Honda (well, most all makes) started using the HEMI combustion chambers (valves on either side of plug electrode), the 'O' rings at the top tend to leak, especially with valve cover movement. And oil seeps down filling the 'tube' and conducts electricity causing a mis-fire.

Just thought that I'd toss that out there since you said that the timing chain was changed lately..
Pull the plug wires and look for oil soaked ends.
If so, get some paper towels and stuff them down in there with a screwdriver or ___ and let it soak it up.
pull them out after and fix the o ring/gasket for that plug


Then, maybe try disconnecting the NEG for a few min and reset the ECU..?

Now granted, this may NOT even be the problem. just sayin.

Another thing could be how aggressive the person was to pull the plugs out. Did the contacts come out the end ? (and the 'mechanic' just shoved it back together?)
Or did they use a tool cutting the wire sheath/outer covering?
Again, just tossing stuff out there that doesn't cost that much to fix.
E