I'm going to bump this, because I'm experiencing very similar symptoms on my 03 Disco II (100k) running 93 Octane. It has rough idle, jumpy/Jerky throttle, especially on slight up hills. I can always accelerate through it...but 2nd-gear-ish is tough. My mechanic has diagnosed it as a bad coil, after checking through the plugs and wires. pretty normal stuff. note* I am not sure what plugs/wires are installed at the moment.

BUT that was 2 1/2 weeks ago. He cleared my codes back then, and planned on having me in when he got in the parts. Hasn't happened yet. Since then, the check engine light has come on, and has periods of flashing several times per journey... It didn't seem too damaging as it began, and it doesn't seem to be getting THAT much worse... but the more i've been reading around here the more worried i've become. This leads me to several questions, and any direction i can get from you guys would be amazing!

1. How much damage am I really doing by driving it? I've read some things about catalytic converters...

2. Are there specific brand parts that I should make sure he's putting in, when it comes to the coil pack(s)?

3. Should I have him change both at the same time? I believe he's only planning on changing Bank A's coil pack.

4. With my SES light on for so long, and the truck defaulting to its rich mixture, am i REALLY gunking up my whole engine??

I have a code reader on it's way right now...and will post them asap. I am a new owner of my Disco, and Love it!! Enjoying learning more and more about her.

 

Hope you have stopped throwing money at your Disco blindly, if you are still having problems, send me your number and I'll call you.