I bought a '98 disco w/83k miles for my daughter. Replaced only the front 2 O2 sensors as the back 2 looked newer and drove 100miles (many starts/stops) ,no codes. Drove in the rain, it immediately threw 2 codes,both 1194.
Cleaned both back sensor connectors and drove 75 miles (starts/stops), no codes. Drove it again in the rain, same thing, after the first puddle, 2codes both 1194.
No other issues, truck runs great

Okay what gives here?
My thanks in advance for your help

 

Could be the wiring, being it's coding for high resistance. You could try taking the connectors apart and putting a healty dose of dielectric grease in there. Or follow the wiring and see if it looks good with healthy connections.

 

I agree, double check the integreity of the insulation/wiring/ and any in-line splices that may be there.

Since it appears to be moisture related, I would strongly suspect an insulation breakdown some where. Look for abrasion from sharp edges, rubbing or other such issues.

Good luck and keep us posted.

 

Do you know when was the last tune up? Most of O2 codes on our trucks are caused by bad spark plugs and wires.

 

Thanks for the quick reply. I haven't pulled the plugs but the wires are brand new. It is absolutely tied to the water as after 6 hours in the driveway without driving - no codes. Start stop repeatedly in this monsoon and no codes.
I am thinking that I have some nicked wires some place low near the sensors.
I need to get the car through emissions, then after I will take a hose and find the problem.

 

First, should have replaced all 4 02's with that mileage. Second, which exact 02's did you install, did you buy the advanced 02 for the new D1's that have the up dated evap. system?
The 1194 code is, oxygen sensor heater high resistance high down stream so don't worry about your wires.

 

mike:
I bought them 2 weeks ago from Atlantic British, did not change the rear sensors because they looked newer and was throwing codes for only the front 2 sensors. The front ones had the wires cutoff .

Thanks again for the help