I've got an 04 LR Discovery coming up with 3 OBDII codes. I know what they say, I just dont know what they mean or how it can be resolved

1. P0130 O2 sensor circuit malfucntion (Bank 1 Sensor 1)
Is this the O2 sensor before or after catalytic converter. Front or back
O2 sensor?
2. P0150 O2 sensor circuit malfunction (Bank 2 Sensor 1)
Is this O2 sensor before or after catalytic converter. Front or back O2
sensor?
3. P0126 Coolant Temp Insufficient Stable Operation
What exactly does that mean?

Any comments or suggestions would be greatly appreciated. Thank you so much...

 

Sensor 1 is front sensor for O2s. But fix heat iisue first.

coolant temperatures too small - the D2 has an engine coolant sensor, and a radiator monitoring sensor. It compares the two. If not enough difference, then this code is generated. Indicates usually that coolant thermostat is sticking open. If you have installed an in-line thermostat mod, this can indicate too large a bypass hole in the thermostat. If replacing thermostat, suggest flush radiator first, so any gunk will be trapped by old stat. Best new stat is one of the soft spring 82C models from Justin at Lucky8. Runs truck 10 degrees cooler or so.

 

Doesn't make any difference which you fix first unless you are overheating your engine.
You need 2 new front 02's. What have you done to your cooling system lately, any new parts or mods?

 

My mechanic friend actually "cleaned" out the original thermostat, flushed out the hoses, checked out my water pump, and re installed the belt, put in a new fan clutch as well. He said my water pump was good, radiator looked clean and hasn't heated up on me since. It had also been leaking coolant very rapidly. Hasn't been doing that either since he did this work. What I'm thinking is that the first time he replaced my belt, I dont think he put it on right from the get go. It was very screechy, noisy when I first turned on the truck and even throughout the day. And I'm thinking that the water pump was working "backwards" maybe and not how it was supposed to. Now that he did all this again, I haven't had any over heating issues or noisy belt for that matter. As far as the O2 sensor, both are the front sensors before catalytic converter???

 

do you think if i changed out the thermostat all together, it would clear up that code??

 

Belt route must be like this Discover Discovery Maintenance Tips, Accessories, Parts & More at Roverparts.com

Check that first.

You can clear the codes and see if the coolant one returns. If it was created by having belt wrong and waterpump running backwards, who knows?

 

Ok I'll try it. Hopefully that one will clear out. Thanks...

 

How many miles on your engine?
I would replace the t/stat with a Soft Spring t/stat from Justine at Lucky8, they run cooler then the factory t/stat. Depending on your mileage, I would suggest you also replace the pressure cap and make sure you switch to Peak or one of the other non-dexcool coolants.
Yes, the 2 front 02's should be replaced.