3642Integra

Hello, 06 Odyssey EX-L 3.5 v6 VVT vtec engine with 198k started with a flashing cel roughly a month ago. Would come and go from time to time when starting the van. Sometimes it would stay solid and other times it wouldn't even be on. Other times it would start a few seconds to a minute after the van had been turned on and flash, turn van off and wait a little, turn back on and it would either be solid or not even on. Got it scanned and codes p0302, p0303, p0304, p0305, p0306, p0300, p0301, p0302, p0303, p0304, p0305, p0306, p0300, p0301 all show up in that order with the main definition stating code p0302 indicates that cylinder 2 had too many misfires within a predetermined period of time. Recommend replacing spark plugs and ignition coils.

So...ordered all 6 ignition coils and spark plugs since we're not sure the last time either were done and with 200k approaching figured why not. Replaced them all, thoroughly cleaned out the throttle body, intake tube and replaced the filter and changed the oil and filter as well. Nothing out of the ordinary in any place touched, all removed parts had normal wear and tear, all spark plugs were the same and oe parts as well as ignition coils and all were replaced with the same oe parts as well provided by the dealer. Button everything up and turn van on and boom no cel or any issues.

Thinking all was said and done proceeded on with our lives. Today cel came on when starting the van, stayed solid, has fine idle, get up and go has zero hesitation and only thing not showing up is ECO not coming on. Stop and get it scanned since I'm off of work and shockingly same exact read out shows up as above in same exact order. So naturally frustrated I double checked everything and it all checks out, plugs all look fine, no oil or discoloration and nothing was backed out or out of place.

Started checking around about it and have found a few things it could possibly be, but who knows? The most common I have seen through reading is throttle body dirty, egr dirty, injectors dirty, ecu needing an update, a rare occurrence even listed the vvt solenoid but I'm curious what that has to do with anything since that is located down near the oil filter and from what I can see it controls valve/timing and possibly vtec or something? Not really sure which direction to take from here. Already replaced everything, already cleaned out the throttle body as well. Any suggestions would be appreciated vs shot gunning parts at it. Thanks in advance.

94eg!

iTrader: (2)

Over time the Honda V6 tends to wear the the valve seats on the hot exhaust side. This causes the exhaust valve clearance to shrink, potentially holding a valve slightly open even when off the cam lobe. A valve adjustment will help if this IS the problem. This is usually only a problem when hot.

Another source of misfire could be clogged egr passages. If one cylinder is getting less exhaust injection than the ecu expects, it could cause misfire. Cleaning the egr ports in the intake manifold is the solution here.

The problem I see with these two issues is that they wouldn't start causing misfire at cold start-up. Exhaust valve clearance is greatest when cold, and I don't think the EGR valve opens until the engine is warm.

This brings us to my 3rd option...oil in the intake manifold. On my 04 pilot, the pcv system was letting a lot of oil into the intake manifold. This caused oil to dribble down into cylinder 1 wetting the plug when the engine was off. This could also be caused by leaking intake valve stem seals, but personally I haven't had any misfire codes since adding a pcv catch can. I think your pcv system is different than mine, so my catch-can thread on piloteers.org won't be step by step guide. If this is your problem, you will know because your plugs will have wet oil on them when the engine is cold. You will still need to clean out the intake manifold before adding a catch-can cause the dripping will continue.

Lastly consider the primary (upstream) O2 sensors. If your old sensors are reading off, they can screw your base fuel maps. I'm not 100% sure this has any effect on startup fuel trims though.

This covers my recent experience with this problem. Good luck.

3642Integra

Thanks for the reply. I just took some time now to remove everything to get the intake manifold off and once I removed the top cover for that I noticed a few small puddles of what looks/smells like oil and moisture blow by from the pvc, very tiny debris as well. I just finished cleaning all of this stuff up, checked egr holes and ports and nothing majorly caked up but still cleaned out as well. I didn't have one on me nor another form of transportation but will be getting a new pvc as well after seeing this. Will also be looking into a catch can. Thank you for the reply and information, it may just be what was causing issue. I believe it is due or near overdue for a valve lash adjustment as well. Not sure when/if it was ever done.

94eg!

iTrader: (2)

Hopefully it helps. I'm pretty sure this was my problem.

Don't expect too much from a new PCV valve. Any condition valve will let oil into the manifold. It's the job of the baffling inside the valvecover to separate the liquid from the gasses and they do a relatively poor job. The catch-can is the best option. I think it would be plumbed in where the hose is connecting your front valve cover to your intake manifold (near the PCV valve).

jiujitsublue18

I am sorry to piggyback on this person's post but I just need to ask 2 questions and since I cannot start a thread yet I have to do it this way. I have a 2012 Honda Odyssey with 107k miles. I was driving this morning and the check engine light came on and the D was flashing. I went and got the code and it said transmission fluid pressure sensor. Everywhere I have looked it says it is a switch and not a sensor. My first questions is, are these 2 things the same? And if so, where is it located on the transmission? I appreciate any and all help and I wish luck to the person that initially started this post.

somick

When was the ATF replaced?

94eg!

iTrader: (2)

It's technically a pressure switch that simply closes the circuit when the fluid pressure reaches a pre-determined point. This can also be considered a sensor as it is "sensing" the pressure of the fluid. I'm not 100% sure if this is the pressure switch in question, but it might be #12 in this photo (part# 28610-R36-004):

https://www.oemacuraparts.com/auto-p...enoid-5at-scat

94eg!

iTrader: (2)

BTW: Back to the original poster, I recently learned about VCM (which your 2006 has) and all the misfire problems it can cause. Consider having a compression and leakdown test performed on the engine to determine the state of health of the bottom and top end of the motor.

somick

The reason I asked about the ATF replacement was that sometimes a dirty fluid may clog the screen and cause problems.

Sam

speedlever

For MY 2006 Pilots, VCM was only used on 2WD models. AWD models did not have VCM.

94eg!

iTrader: (2)

Then definitely do a valve adjustment. You will need a bunch of gaskets to make it happen. I used the victor reinz plenum & valvecover gasket sets. They were on clearance on Rockauto and cost about $25. Not sure those deals are still around. The brand seemed as good as the Honda stuff I used the previous time. The valvecover bolt grommets are always a nightmare (OEM or Aftermarket). I might recommend using some silicone grease to get the new ones onto the bolts without damaging them. You will probably have to use a hammer & deep-socket and a block of wood to get the old ones off. Also the victor reinz spark plug tube seals are very tough to get fully seated into the valvecover also. Some grease may help there too. Perhaps spend the extra $$ and use OEM valvecover gasket sets instead (the aftermarket manifold gaskets were perfect).

BTW: If you knock the throttle body off the manifold cleanly (use the handle of a hammer to tap it loose) you won't have to replace it's gasket. This gasket is paper and a PITA to get cleaned off. So long as it doesn't shred, you can reuse it.

Also clean the crap out of the intake manifold while it's out. It's a nightmare from all the PCV oil, as well as the EGR buildup. Scraping out the EGR ports and passages with a small flat-head is well worth it. Getting all the motor oil & varnish is not nearly as important as the EGR buildup. Your year pilot may have less oil from a more advanced PCV setup anyways (won't know till you open it).