Hey guys, it's been awhile, I hope everyone has been doing well.
So my check engine light has been off for quite awhile until I took a 3 hour trip up north.

My Ultragauge pulled up these three codes:
P0300 - Random/Multiple Misfire
P0307 - Misfire on cylinder #7
P0134 - Oxygen Sensor 1 bank 1 - No activity

A little bit of background:
Plugs are Autolite Double Platinum - 24k miles on them
Wires are Magnecor 8mm - 13k on them
o2 Sensors - 112k (Ordered new ones tonight)

My question is, does anybody know if the o2 sensor would be connected to my misfire? If not, do plugs go bad this fast? I don't have any tools with me since I'm 3 hours away from home, so I don't have the tools to check my plugs. My Rover seems to run "ok", but there's a definite miss when she's idling. Any constructive advice would be greatly appreciated. Thank you for your time everyone

 

Misfires are most likely plugs and wires. Any auto parts store should sell them and the tools to put them in. Note - older Discos have a weight sensor that detects when enough tools are not loaded. The O2 sensor could be a wiring issue (like water or oil leaked on the connector, etc.), or just loose. This is not the signal for CAT damaging multiple misfire. See attached. The Bosch manual says it is OS2 circuit continuity for that code number. Code readers frequently have generic text messages, that's why normally we ask for the code numbers.

 

So why the urgency now since your lights have been on for quite some time? That light is there for a reason and should not be neglected, in your case 1 misfire and some tired 02's probably haven't hurt anything but what what if it were a critical fault, you could have cost yourself a set of cats or en engine.
So go check your plug and buy 4 new 02's and get your truck running better, might even save on your gas mileage.