Okay I have a 99 Disco 2 4.0 2 codes popped up 1171 & 1174 sounds simple. So I bought 2 brand New Bosch O2 sensors and replace both front O2's also I cleaned all connectors with electrical contact cleaner and I also spray cleaned the MAF with MAF cleaner and let evrything dry for 45 mins. Now the issue is the truck runs and drives good but it idles rough now, then a day later these codes popped up P0154, P0135, P0155, P0130. Its weird cause everything is new and hooked up correctly. I also double checked the conections again. Please I hope some one has a solution. Also the truck ran fine before I changed the O2's.

 

I would check your plugs and wires.

 

plugs and wires are less than a month old

 

Anyone know if the O2 sensors have fuses or relays and if so Which ones.

 

F2 under hood, and main relay - it powers up a bunch of engine management stuff.

 

Is your cel light on? I would check your 15 amp engine fuse, might be blown. I think its the 2nd or 3rd one from bottom. i had a similar problem and it was the fuse.

 

Yep, two votes for the same fuse -

 

40 amp fuse fifth one up from the bottom fixed my problem very similar

 

I checked every single fuse In the truck and they are all good. Now what's next, Im still stumped.

 

What plugs and wires are you running?