Woke up the other morning, started my car warmed it up a bit. Drove off and right when I drive off my cluster goes crazy. VSA is on, caution light is on, CEL is flashing! I'm going out of my mind. Use my OBDII scanner at home and comes out with P0138 - secondary heated oxygen sensor circuit high voltage (sensor 2) and cylinder 4 misfire. Which I'm assuming is my o2 sensor because my cat might possibly be loose. I heard a slight rattling for awhile, but I thought it was nothing or normal engine noise. Just posting to see if anybody has any bright ideas on what to do?

It's a MY07 with 70k miles, bought it with 60k on it.
My assumptions:
Spark plugs are overdue for a replacement causing the misfire.
Replace the spark plugs with OEM NGK.
Cat honey comb is loose and broke my o2 sensor.
Planning to just gut the cat(cheap quick fix for temporary) and replace the o2 sensor.

Do I have to buy defoulers or antyhing like that for the o2 sensor since I'm gutting it?
Are all o2 sensors the same for Hondas? I remember for my 96 Civic it was only like $50. When I search for an S2K o2 it's well over $100.
Thanks in advance.

 

i got the same thing here( cilender 4th missfire.) this weekend im replacing ignition coil and all spark plugs. I hope it fixes it, post up your results.

 

Luckily, I have a few friends with an AP2. So first we swapped spark plugs, didn't work. Swapped the coil pack right after, PERFECT.
Ended up just buying new plugs for good measure and a coil pack. Car runs fine now.

Waiting for ECU to run through it's cycles and we'll see if the cat and o2 is fine. But everything seems okay, I have no idea why the cylinder 4 misfire caused by a coil pack would give me the P0138, but I'm glad it's gone.

 

You should try moving the coilpack to see if the fault follows. If nothing, try the same thing with the injector.