Re-occuring P0300 Error code but only when it rains?

Hi, New to the forum! Absolutely love it. I've got a 2005 V6 manual 4x4 Tacoma, 145K miles mostly highway with off road mixed in for fun.

My issue is I randomly get a check engine light notification with an associated P0300 code. I know what it means and have been to 2 different dealerships and 2 respected independent mechanics who can't find the issue. They change the plugs, check the timing, clean the MAF, but don't really give me a true root cause to fix once and for all. This has happened probably 3 times over the past 2 years. Latest instance was monday on a run to Lewisburg, PA. What happens is the engine gives a hesitation slight to severe at highway speeds, I can press the accelerator to the floor with no increase in speed and then the check engine light comes on with the engine running in a rough fashion, it feels sputtery and weak. I usually pull over for 15 to 20 minutes with the engine off. Start it up again, the check engine light is on but the engine is now operating fine with plenty of power. The one constant when this happens is that it is always raining when this happens and I am operating in cruise control mode. I have never had it happen when I am driving in cruise control and it is dry out. WTF? Any suggestions?

Thanks,
Graham

 

If you've had it to two different dealerships and two other mechanics, then I'd say you're pretty much SCREWED.

Because honestly, if 4 different shops can't figure it out - that's pretty damn pathetic.
P0300 Random/Multiple Cylinder Misfire Detected

Did you do any researching online yet?
Here's some reading for ya to get you started. Google is your friend.
http://www.parksoffroad.com/tacomamods/maintitems/enginecode/cip0300p.pdf
http://www.obd-codes.com/forums/viewtopic.php?f=1&t=3406

 

I have googled the shit out of it for sometime now and read till my eyes bleed. Knowing how to google is not the problem smart man. It is finding competent mechanics that can fix a vehicle

I agree that it is pathetic.

 

At this point - take the information you've read online and start trouble-shooting yourself.

You're better off doing it yourself and saving yourself the $$. Then, if you've found the problem - you can decide whether you want to actually repair it yourself or TELL a mechanic exactly what you want him to fix.

 

perhaps your getting water in the intake somehow?

 

Has this happened to you when you are not using the cruise and its raining? Or only when the cruise is on?

 

i had a very similar problem with my old acura... and it was throwing a similar code and engine hesitation.. and it turned out to be the distributor/distributor cap. it wasnt sealing properly. i guess with the heat and moisture it was acting up.. replaced the distributor and the problem went away... however i dont know why it only does it when the cruise is on :S