Nice job. Hindsight is always 20/20. I only knew it was oxygen sensors because I have had the same thing happen a bunch of times.

 

I'm having the same issue w my 04 DII w nearly 206k miles on it. #4 misfire only when the engine is stone cold. Once warm it's fine. I replaced all of the O2 sensors previouslly then started shortly after getting the #4 cyl misfire so I replaced the plugs wires and coils. What a PIA changing the coils is. The wires and plugs definitely needed it.

Why would O2 sensor cause the misfire? Not getting a o2 sensor error. If I unplug the O2 sensors would the misfire go away? Which O2 sensor would cause the #4 misfire?

Any advice is appreciated!

 

Coolant leak into cylinder #4 when cold causing misfire until coolant is burned off spark plug?

 

Could be. But I have found, the cars go into closed loop after 30 or so seconds, the trim starts to go up on ONE bank until it starts to miss and then will fault and go open loop, and instantly run fine.
Most of the time you only get a missfire on one cylinder for a code.

 

Ok checked codes today and also have P0159 circuit low, response slow bank 2 sensor 2. Which sensor would this be? They are new but since I got them from eBay i don't trust them. Two of them were wired wrong at the plugs

 

I'm thinking you may want to start a new forum with your issue. I don't think this issue relates to the original issue of Cylinder 4 & 6 misfire.

 

Sounds like the same issue although my 02 wires don't apeear melted.

 

bank 2 sensor 2.
Bank goes with cylinder #2 to help you remember.

Cylinder #2 / Bank #2 is the right side - from sitting in the driver's seat.

Sensor #2 is always the rear sensor.

I did a write up on O2 sensors on a D1 - but it still applies to a D2

http://jeffreyfall.com/landrover

The front sensor controls the mixture - Sensor #1.
Sensor #2 just checks if your Cat convertors are efficient or not.

 

i didn't have an O2 code thrown and i had multiple misfires. When someone posts to a forum then this means you've looked at the RAVE manual and researched your issues on the other forums. If you can't find a solution to your exact issue then post a thread. The problem with some of the forums is that we get off the original topic and these forums are here to be helpful. making the solutions so broad isn't helpful, so staying on topic and narrowing down the solution is what we need to do in order to have productive forums.

 

Alright...some bad news. My light returned after a few miles on the Rover and looks like i had incorrectly wired the O2. i swapped the "Input"/"Output" and the code didn't return. I am now back to square one and still have the Cylinder 4 & 6 misfire and the random multiple misfire. This is still occurring at low RPM/idle.

I fear i now know the reason the previous owner decided to sell this beauty! i am now going to try my last resort and pull the plugs from 4 & 6 and use a little Lucus cleaner ontop the pistons and in the gas tank. In the back of my mind, i know i'm just pissing in the wind, but hopefully i could chuck this up to just mega carbon deposit after the below find with the improper maintenance from the last owner.

I did an induction cleaning, changed the oil, and oil pressure sensor last night for the first time since i've owned it. The previous owner said they had just changed it, but after the mess i've discovered i figured he was lying about that too (I've only driven it 1000 miles since i got it). I've changed alot of oil in my life and i can say that the oil looked to be older than 5000 miles of use. I replaced it with 10w40 and a bottle of lucus additive. Forgot to mention, I also replaced all the vacuum lines for the secondary air system.

I cleared the codes and on my way into work this morning they returned as soon as i went from reverse to drive. I still notice that it only occurs at low RPM and idle, but not every time. She drives great other than the rough idle sometimes at stoplights. If all signs are pointing towards a valve job, i feel i am just going to drive the sh*t out of it until she stops running and then 5 years from now my son will have a project with the engine rebuild.

Any advice is always much appreciated. I don't know how else to clean valves other than the usual additives. I also don't understand why cylinder 4 & 6 would continue to misfire? do valves usually die in pairs?

One last thing to bring up, i do not feel i have a leaky head gasket because i saw none in the oil and have no loss of fluid or pressure in my reservoir tank.