On the way home today when I was idling the car ran really rough and almost stalled a couple times. The CEL did not come on and I double checked with my code scanner but no codes were thrown.

A few days ago I changed the plugs but drove probably a hundred miles since with no issue. This morning I cleaned the throttle body with proper cleaner and drove about 10 miles and it was fine. 8 hours later i go to drive it home and it starts acting up with the symptoms mentioned above.

Opening the hood, the only thing I can find wrong at a glance is that the air filter on the after market intake basically fell apart. Its a tapered cylinder with a conical internal piece (JWT Pop charger air filter). The internal piece completely broke away from the outer cylinder of the air filter. Would this cause really rough idling? Basically too much air flow that is partially unfiltered?

I had already ordered a replacement air filter because I noticed it was all cracked but it won't be here until Tuesday. I'm planning on dropping it off at a shop in the morning but wondering if I've already found the culprit. Help!

 

The air filter could be the culprit; and that fits with the probable cause, a vacuum leak.

 

I would just wait for the new air filter and clean your mass air flow sensor... Lucky you changed your spark plugs without finding your pluggs skinny dipping in oil like I did.

 

Well actually one of them was...but it would've thrown a code if it was a misfire or maf sensor

 

Also if you unplugged your battery and or reset the computer recently the car tends to idle really low afterwards... I hate resetting the computer, I always think its going to stall in me.

 

Apparently the design of the valve covers sucks... I just made my $400 purchase so I can swap them out with new ones and hope for the best...

 

So not just the gasket? You're replacing the whole assembly?

 

Thats affirmative, apparently the gaskets for the plug tubes are not replaceable, if you want to fix it right you gotta suck it up and replace the whole thing...

I didnt even change my plugs I pulled the first coil found the mess cleaned the best I could and put it back in.

 

Which cylinder? Mine was 6. It was the first one I pulled and I was pissed but changed the other 5 too and they were all bone dry.

 

I pulled #5 passenger side most rear, I was also pissed haha and put back... It will be interesting to see how many more are saturated. I have 78k miles on my car.