P0300 random multiple misfire

Since you have an 06, have you checked or replaced the OPDA? A worn OPDA gear or cam gear can cause the mult misfires.

For the P0431, the pre cat to manifold bolts loosen and can cause the cat codes. Also, bad O2 sensors can cause it. Only use NTK/MOPAR if you replace the O2s.

The "sending unit" for the oil pressure gauge is just a switch on the passenger side of the block. Check the wiring first. If you want to know if it actually has low oil pressure you will need to check it with an actual test gauge.
 
Haven't done the OPDA yet(it's sitting in the garage) it hasn't been making any noise so I've been playing "hear no evil see no evil"
Going to leave the thing here at work tonight and come back tomorrow with tools and throw parts at it
 
Interesting…..I have an 06, 4.0L, with auto transmission and the crank position sensor is on the passenger side bell housing just aft of the starter.

You're right. Some manual and older Jeeps its driver top.


OP its where Bigfoot said. I as well have an 06 with the auto. It is right by the starter passenger side. Easy to access too
 
Thanks for all the help
Top right makes sense, since my heater core dumped almost 2 gallons of coolant right in that very spot
 
Ok, new Mopar crank sensor, new Standard ign coil and 6 new XP985 Autolite plugs and no change
Anyone have a guess?
Starts great, idles fine, pulls to 3200 rpm then starts breaking down
 
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Ok, new Mopar crank sensor, new Standard ign coil and 6 new XP985 Autolite plugs and mo change
Anyone have a guess?
Starts great, idles fine, pulls to 3200 rpm then starts breaking down

I had a random misfire code when my cats failed.
 
Well that's not what I wanted to hear but getting random P0431 codes last week might support that
 
Well that's not what I wanted to hear but getting random P0431 codes last week might support that

Mine wouldn’t let me go much over 55 mph without going into some sort of limp mode when that happened. I believe it had to do with the back pressure it was creating in the system.
 
You're not my favorite person right now even though I think you're probably correct
Is there a catalytic converter to stay away from?
It's been down on power up high/freeway speeds for a while and it's started being rattly on cold startup
 
Well I hate to spend that kind of money period but Summit has the Flowmaster cat on sale so I ordered it. I can't think of anything else that might cause this and I need this thing running as it's my daily driver. I have 4 new O2 sensors ready to go
 
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Ok, flowmaster cat came in yesterday, they got the Jeep in the shop this morning and sure enough the rear pre cat guts are whittled down to the size of a baseball and sitting sideways blocking the pipe
Our tech is going to go ahead change all 4 O2 sensors while he can get to them easy

Glad you got it figured out.