2006 odyssey misfire and bad idle-Tried everything
 

Hi all, I have an 06 odyssey with random misfires and a bad idle. 132k miles.

I haven’t tried everything, but I’ve tried a lot of stuff mentioned on forums.

it always gets the same codes, multiple random misfire and some, if not all cylinders misfiring.

I have replaced the fuel pump, spark plugs, alternator with a used one and done the valve adjustment.
engine compression was 210 on all 6 +/- 5psi before the valve adjustment, have not checked since I adjusted them.

the fuel pump was the only one that made some difference to the idle, but the misfires came back after a few throttle revs.
The new plugs on the lower 3 cylinders are as follows with only 30 minutes of idle time on them. (This was before the fuel pump was changed)
cyl 4- Black as of was running rich.
cyl 5 looks normal?
cyl 6 looks like it’s barely firing.

I have also checked each coil connector to make sure it is receiving power and signal
the same goes for the fuel injector connectors.

The auto parts store sells the fuel pressure regulator, but I cannot find where it is located to replace that next.

Any idea where to go from here?
Thanks.

https://cimg5.ibsrv.net/gimg/hondafo...bc617f270.jpeg

welcome to the forum i would suspect coil packs are starting to fail. you have fuel and air. with good compression, the only thing not changed is the coil packs. my 07 Fit coil pack failed at 180k miles. plug misfire, change plugs and still misfire. changed all 4 coil packs and 295k miles still smooth.

Thank you and Thanks for the reply. I will try swapping those this week.
I bought 3 new ones but returned them because the misfires were on almost each cylinder, so there was no way I could know if 1 or all coils were bad.
I also notice that the idle is a lot smoother if the alternator signal plug is disconnected.
I have yet to find the fuel pressure regulator location or test the fuel injectors.
move also cleaned the throttle body and checked for vacuum leaks, I did not find any.