2002 discovery 120k miles
Just started doing it check engine light flashes then stops
Replaced spark plugs and I think I replaced the wires too 20k miles ago
The wires on it now are the blue ones STI
Not sure yet if it's the coil or not but if it is where do I get one without spending a huge coin
And also could the crank position sensor be the issue I read something about that somewhere
I did drive through a HUGE paddle a week ago or so
As always thank you all very much

 

Just went through this with mine. Same codes and it ended up being the front O2 sensor on that bank. Only figured it out after replacing wires and plugs.

 

No, CPS will not cause a misfire. When they go bad, the engine will simply die or fail to start. The starter will still spin the crank though.

 

Wow I actually had a o2 code not to ldo by ago but kind of ignored it
Wow will replace that and report back thanks a lot

 

If memory serves me, 0300 is a general misfire code. I did the coils a few years back. Even if you are not an expert wrench turner the Rave will get you thru it. It was my first "major" foray into my rover. I laid out a moving blanket and numbered ever nut and bolt with a piece of masking tape below it.
FYI- Coils at BPU: Range Rover Discovery Ignition Coil Pack ERR6045

 

Thank you

 

Well I replaced the O2 upstream on the same side as the misfire and nothing
What do you good people think I should tackle next
Thank you

 

Every time I have had pO300 it was the MAF. If you know someone else with a Disco, swap MAFs for a few minutes and see if it goes away. It did, twice, for me. Or buy one local and if that doesn't fix it, return the MAF.

 

Ok will try that too
Anybody else feel free to chime in
Thank you

 

Just my 2 cents worth:
I would look very carefully at the plug and wire to cylinder 4. In my experience, I have had the random misfire code (P0300) associated with a single cylinder misfire. It is as if the misfire on one cylinder occurs so infrequently the ecm cannot detect which cylinder it is, so it throws the random code.

I suffered through the same issue for months with just a P0300 until it finally got bad enough to "show its face" and come up with a P0305. Changed the wire and the truck runs better than it has in years. I could have just changed all the wires, but like yours, they were fairly new, and I dislike "shotgunning" a problem, and prefer a solid diagnosis and a single-failed-part replacement resolution.