Hello all.

Yesterday the Discovery was running fine. Then the check engine light came on and my ScanguageII showed P0130. According to my OBDII list that is a oxygen sensor cycle fault. I had both(2) FRONT upstream replaced at 68k. The rear are factory original 87k on them now. It had a sporadic rough idle at stop lights when below 1000rpm

Today: Same P0130 code and then some misfiring and a whole bunch more codes. These are the same symptoms as my other O2's going out. It smelled like unburnt fuel and overall stinky. Thats probably the misfire codes and lean fuel trim. My guess is bad rear 02's. So what does everyone think. Need a little help, before I go out and buy two O2's today.

P1305 Misfire Cylinder 5
P0307 Misfire Cylinder 7
P0303 Misfire Cylinder 4
C1008 ???

I have 2 Bosch downstream on order from AutoRoZone.

 

Nope.
You need a tune up, thats new plugs are wires.
When your plugs and wires go bad the spark gets weak and dumps unburnt fuel down stream and the excess fuel sets off O2 codes.
That is why you have mis fire codes and raw fuel smell.

 

Hi Spike thanks for your reply. I fixed it today!

I started off with 2 new rear O2 sensors installed. Started it up still rough idle no change. Those were originals with 87k on them.

I also bought a spare front(upstream) Bosch O2. I remember I had done Seafoam and BG intake cleaning with in the last 2 weeks. It had never been done on my Rover. I knew if you do a lot intake cleaning it can foul your O2 sensors. Bingo! I checked the Drivers side left upstream and it was all car-boned up. I switched out my new one. Then checked the front upstream passenger. It was clean. I started it up drove at 60mph up the hwy. To help burn off the carbon on my fouled plugs. It runs really smooth now.
The front O2 sensor was less than a a year old from Advanced. I dont think it was bad, just carboned up, but they let me exchange it out for free.
So all it well...smooth idle. Already have Magnacore wires back at @ 68k and new E3 plugs with in 4500 miles. I may check the drivers side bank to see if they are fouled, but it runs smooth now.

So I guess the moral to the story is. Don't do too much Sea-foam or BG intake cleaning if you have never done it. It must knock down a bunch of carbon....and can foul your O2's. Then the O2's are all carboned up and cannot read emissions correctly. Boom all the codes like they are failing. Maybe a suggestion to clean them with alcohol or acetone after repeated intake manifold treatments!

I knew these exact symptoms since I had already fought this battle at the dealership about 1.5 years ago before I new anything or had found the forum. Today I also spent about 2 hours reading everybody else's posts about my same P0130 code on 03's Discovery's. It pays to do your research. Finally fixed one myself and no nightmares this time!
I'll be interested to see if my gas mileage improves a little with 3 new O2's all the way around! So 2 $68 O2 senors and a fixed rough idle. That's a lot more than many real Rover mechanics can boast since these Rovers are so finicky with it comes to a idle problem.

P.S. The OEM brand O2 Sensor socket works great to break O2 sensors loose. Well worth $9.99 @ Advanced or RutRoZone