2003 X Type 2.5L with about 150K on it.

Driving home last night cylinder 5 dropped out on me. While reading my codes bad cat came up. Trying to diagnose O2 sensors I'm coming up with weird numbers for the upstream and downstream sensors.



I am new to reading codes. Am I able to diagnose a bad O2 sensor while I have a misfire/ dead cylinder 5?

My gut tells me I have a bad cat or 2.

2018 new plugs, coil packs, upper and Lowe intake gaskets and the 2 green gaskets passenger side.

If I can provide more information please let me know.

Jason

 

That's a painful tool to try to figure out! What is it?

What are the actual DTCs?

 

jmott, if you lost a cylinder, i would fix that problem first. Odds are, it will fix your O2 sensor issue too. Based on what you are saying, I would venture to guess you have a valve cover seal that is leaking a little bit of oil into the plug well and you have a coil that is shorting out to the block vice through the plug.

But, like JagV8 said, give us the DTCs and then we can make sure we help you with a possible solution using the best data that we can.

 

here is the codes I have.

 

jmott, cylinder 5 is the one nearest the brake booster on the back side of the engine for you. So, the only way to access the coil/plug is to remove the intake. Not a hard job, but, this is going to add some time to the job. From there, I would say to swap the coils between cylinders 5 and 2 (2 is directly behind the passenger headlight, which can be accessed at any time). Also look in the plug well for any signs of oil. I am betting you will find some oil down in there. It probably would not be a bad idea to pull that one plug and make sure that the plug is not damaged and then to take a wire brush to the plug to clear any carbon build up on it.

If you find oil, you will probably be good for another few thousand miles before you will be pulling the back valve cover to replace the seals there. If the misfire moves to cylinder 2 (as noted by a P0302 and P1313 code), then you have a bad coil. If things stay as they are now, then you have either a wiring problem to the coil or you have a problem with the injector.