...2003 disco--104,000 miles---codes are as follows

p0301
p0306
p0300
p0150--bank 2 sensor???

hope this makes sence to someone out there. Wifes truck and its mis fireing very bad...

any help??

thanks

 

Sounds like you need new ignition wires (get magnecores), maybe new plugs (if it been a while). And maybe need to replace the front 2 O2 sensors but if you have not replaced them in a while (60,000 miles) may be a good time to do all 4.

I would do the wire and plugs and if you still have the O2 sensor code then do the front O2 sensors.

 

When was it last tuned, were the wires replaced, have the 4 02's been replaced yet and what octane gas is she using????

 

...I have replaced the two upstream o2's about 30,000 miles ago--and the plugs around 5,000 miles ago.--never plug wires! Heard they are nightmare to change. BUT if that is what it takes tell me what to do to get this truck running better.

thanks everyone--they guy at auto zone just said it had a random misfire and those were the codes--not much help.

If it helps--this thing is running ver y very bad--no power at all and shakes and vibrates like its running on 6...always always put 93 in it!

 

Again what octane gas are you running, why replace only 2 02's when 4 are needed, especially if you are over 100,000 miles, to get the fuel ratio balance for both banks.
Sure the plug wires are hard to install, but wait till you have to replace your cats cause you allowed them to burn up from the misfires.
Order a set of 8 mm Magnacor wires, replace your 02's and plan on decarboning your engine.

 

Get the magnecors from here:

http://www.apexperformance.net/CartGenie/prod-1155.htm

They are annoying to install but I did it and knew nothing about engines before I started. There is a good tutorial around here buy a guy named deep blue or something like that. You need to do the wire though it will clear up your misfires. Don't cheap out on wires either.

 

....I will order the wires tomorrow. Did I read you had to take intake off to change them??? also the reason i changed the upstream ones is because I was told the downstream ones "never go bad" anyway--I will change the wires as soon as they get here and go from there--what other things could it be other than wires and o2's---what about the coils??

thanks again

 

So, don't always believe what you hear.
When you get the wires, send me your tele number and I will walk you thru this, without pulling the manifold.

 

sounds great. I just PMed you and I will send you my Number wehn i get the wires.

thanks again

 

I'm running into the same problem on my 99 Disco II, 138k miles. Is the '99 similar to the '03 in the sense that I should be able to replace wires and plugs without removing the intake manifold?

I'm looking to sell my Disco soon and am not interested in putting a ton of $$ into it right now. Are prestolite wires ok? I've found them in stock locally for $55 vs. $130 online for the magnacores.

Thanks!