Hey everyone, I was driving around, and all of a sudden my car started idling rough and I got a CEL.

I checked it with a scanner and this is what I got.
P0301
P0302
P0303
P0304
P0305
P0790

Please help! Why would all these codes show up spontaneously

My car is high milage 300000 miles

 

i was getting similar codes.
changed fuel injectors, no misfire for a day or two. then same problem. i just put in new spark plugs and is running great. still to early to tell bc i just replaced them yesterday.

any maintenance done to it lately? did u clean the egr port? common problem

 

this mite sound crazy but my buddy is a tech at acura and he was telling me that j series motors have that problem and all it needs is a valve adjustment and hes i rite told me this because i own a 99 cl with a 3.0 v6

 

^ yes that can be a cause of misfire. that is expensive work there usually due at 120K. If you drive the car hard constantly you may need one sooner

 

tight valves on these motors are common like the transmissions failing.
what are the data list readings ?
check the map voltage at no load idle when fully warmed up

 

1 bad coil pack can gave u multiple misfrie code. If it is me and I'm an Acura tech I would let the car run and than unplug each coil pack one at a time. The car will run rougher but if the there is no change than that is the bad coil pack. The map sensor is a good thing to check too Car fully warm map should be 1.00 volt's

 

How do I go about unplugging these coils without getting shocked?

How did the poster finally find a solution?

 

IT SEEMS YOUR VALVES NEED TO BE AJUSTED I HAD THE SAME CODES ON MY COUSINS CAR

 

had the same problem. Here is how i fixed it. Read everything i could find about it on the web. Then i narrowed it down to either the coils, fuel injector, possible valve adjustment, cat converter, EGR. I had the car running and pulled off one coil at a time. The good coils when disconnected made an obvious drop on engine power. The bad one did not change the engine power. That was it, one bad coil. I replaced the bad coil and used a bottle of seafoam for the fuel injectors and now it is running superb! The dealer wanted 987.00 to fix it. It cost me 60.00 and a lot of reading.