I have a disco 2 '03 with 91 k miles. The other day the Check engine light came on out of the blue so I got the codes and needed some suggestions. I've changed the air filter, and had to change out the MAF sensor 2 yrs ago so I don't think those are the issues. Here are the codes, P0150, P1174, P0174, P0159. I've looked at several sites about these, and they all hint at it being a o2 sensor prob. If so, how can I check the o2 sensors to see which one is gone? Thanks

 

if you check the codes online, they will give you the info on which side (bank) and front or back (before the Cat. Converter or after) this gives you the correct one to change..

 

well, you have lean codes and it looks like your right front may be going out. You are just getting to the time to replace your O2 sensors. When replaced, they need to be done as a set od your engine will run lean/rich on opposing sides. Since you have a newer MAF and no 4th gear code, I would say you are due for new O2's

 

Cool! Do you know which side bank A is verses Bank B? Thanks

 

A = drivers
B = passenger
1 = front
2 = rear.

This is for LHD models

 

So you suggest I replace both fronts?

 

I suggest you do all 4 at the same time. You will get better fueal mileage as a bonus. They will last about 100K.

 

Hi, my name is Joe and own a Discovery SE 2003 w/ ~82k miles (USA).

I got the similar problems with the O2 sensor, replaced it and the problem came back. I check the errors and they relate to cylinder misfire, and O2 sensor P0150. The first error is always P0150, then other show up (P0300, P0308).

Note: the first time I read all codes they included the following: P0150, P0174, P1174, P0300, P0308, P0304. I thought they all related to the O2 sensor, so decided to change that one sensor.

Are they related? Do I need to change all sensors in order to fix the problem (it wasn't clear by reading your postings), regardless the only sensor error is P0150?

thank you in advance for your help,
joe

 

First of all the 150 is a malfunction form bank 2 senor 1, has nothing to do with anything else.
Replacing all 4 would be a good idea, will certainly take care of the 174 and the 1174 codes. The 159 just can't handle the front sensor being down.

 

thank you,
joe