I just got the o2 sensor in today and I have to replace it anyway, so I will let you know. I think it has to be the o2 sensor, as the misfires are all on the same head on the same side as the o2 sensor, make sense? Or am I just being hopeful?

 

I don't know about rovers, but a bad pre-cat o2 can cause misfires in other makes.

 

When are you going to stop wasting your time playing with the COS, coils, MAF and everything else and realize, if you think about it, none of them can cut out an entire bank.
I told you that over the last few years a few other people had the same issue, wasted the same amount of time and money, didn't find the problem and sent it to a really well qualified mechanic.
Same holds true with your 3 amigos, why do a possible repair when in fact there are 16 reason why they will come on and with out scanning and finding the exact codes, you are again, wasting your time and possible money.

 

Again, you are guessing, 02's will not cause misfires and should not be replaced, especially when you have no 02 codes.

 

X2

OP, have your tried a simple seafoam treatment?

 

Mike, thanks for your assistance, but I would rather you not comment anymore. You have a terrible attitude and frankly after reading your several replies you have made on other posts it is clear to me that you think you are superior to everyone on this forum and don't tend to treat anyone with any respect.

As for guessing, I am guessing on a lot of this, because no one seems to know and I just bought this vehicle and have no idea of its history. But I'm not guessing on the O2 sensor, I'm throwing a sensor 1 bank 1 code, which happens to be on the same side all my misfires are on. And as for O2 sensors not causing misfires, it's my understanding experience that O2 sensors can and do cause misfires.

So, mike, in closing have a great life, but please refrain from offering me your "words of wisdom". I bought this truck because I like tinkering and 4x4ing. I joined this forum to be around other like minded individuals. I clearly don't want your advice.

To everyone else, as always, thank you so much for your advice and help and I look forward to keep contributing to this forum.

Cheers!

Rocky

 

Sloan, as stated, I am throwing a P0135, which is an O2 sensor code.

 

Well looky here, I just bought a Disco II today with the exact same issues pretty much 3,5,7. I did because the mileage is sweet and the thing is a clean Cali Truck and this issue got me a deal and a half with a frustrated owner. I ran through some basic headgasket and coolant tests, zero indication of leaks. I got the wires, spark plugs done recently by previous owner, but I will check gaps thanks to this forum. After 2 days reading the forum Im going in this order.

-Pull Codes
-Seafoam her, because I want to and its the cheapest
-Pre-cat O2s swap out
-Coil

How did you come along on this since it has been a few days, still looking for the holy grail on fixing it before I dive in. Not gonna hijack the thread, gonna post my own, but I wanted to touch base

 

gpelite,

I replaced the precat O2 sensors and did a seafoam fuel treatment and low and behold, the problem is solved. My advice, do the seafoam and if you have O2 codes, get an ultraguage, I could clearly see my O2 sensor wasnt working. And the seafoam worked as advertised and I could tell it ran much better. One other thing to note, only use supreme gas, it runs better.

 

Also, thank you all so much for the help!