Land Rover Repair: 1998 Land Rover O2 Senser, o2 sensors, engine coolant temperature

Question
Hi I have a 1998 LR Disco and my check engine light started coming on . I checked the code and got 1191 or 1193. It keep changing. I replaced the o2 senser downstream behind  the cat on the left side, the one on the drivers side. It did fine for about a week and check light came back on.Code 1193.What up? Thanks for all your help.Mack

Answer
Hi Mack,

I've heard someone have this problem once before....he unplugged and reconnected the sensor and his trouble went away.  Just a thought...

With your OBDII reader close by...do the following to test out your O2 sensors:

Ignition on for 30 seconds
Engine start
Engine idle for 2 minutes
Engine Coolant Temperature (ECT) less than 140°F (60°C)
2 light accelerations,
0 to 35 mph with light pedal pressure
2 medium accelerations
0 to 45 mph with moderate pedal pressure
2 hard accelerations
0 to 55 mph with heavy pedal pressure
60 mph cruise for 5 minutes
50 mph cruise for 5 minutes
Engine idle for 2 minutes
Check for fault codes

In order to trip a fault, the problem has to have happened at least twice.  

Coolant and oil are an 02 sensors worse nightmare.

Most times, P1193 spells sensor fault.  Some have said it could be wiring or even connector trouble too.

Best of luck,

JohnMc