Hello guys,

My wife started to complain about no changing to higher gears on her
99 Disco II (50 k miles), lack of power and misfiring noise.
I checked sparking plugs and gearbox oil and it’s OK.
I didn’t get any check engine lights on panel but after a scan I got P0155 (O2 front sensor RH Bank) and P0171 (System too rich LH Bank).
The car is misfiring and has a strange noise at idle, like a leaking in the admission. I tested the car on street and it doesn't go over 3000 rpm and 50mph.
What do you think? Do I need new O2 and MAF sensors ? Any other ideas?
Thanks

J Reali
East Timor

 

Send me your number and I'll call you this morning.

 

Dear Mike,
it will be great, but I'm not in USA, so I don't want you spending in overseas calls.
Maybe I can call you?

 

Mike,

I'm on skype (in case you can help me)
jose_reali

 

Call me, I am DiscoMike2. If you want to let me know when so I can keep an ear open for you.

 

Mike,
just an update:
I changed transmission oil and filter and the gear change is a little better. Still delaying changes specially when cold. I cleaned the codes yesterday and today I got P0150 instead of P0155 and P0171.
I'm waiting for the O2 sensors to arrive from AtlanticBritish. Once I change them all I come back to report.
Thanks for your help.

 

How cold has it been. I have noticed that when it gets real cold the tranny will not shift into drive untill the fluid has warmed up. This will usually only take a minute or two. This may be what you are noticing.

 

Sometimes when the fluid id getting old and the tranny is getting into higher mileage, the governor will hang up until you get close to 3000 RPM's, usually only on the first shift.
Might want to change your fluid.

 

OK Mike, here it is:

I changed transmission fluid and O2 sensors. The strange noise is also gone. It was a leak on the exhaust manifold now solved. The problem now is: Still not changing gears adequately. If you push hard the gas pedal, rpm goes up to a limit of 3000 but the gears doesn't go up. It only change gears when you release the gas pedal.
But if you push gas pedal progressively, then shift all gears in an apparently normal way. What do you recommend as next step?
Thanks again

J Reali
99 Disco II in East Timor (40k miles)

 

You need to change the transmission filter, changing the fluid is not going to solve your problem, you MUST change the transmission filter.
When the filter gets clogged it will cause shifting problems.