I just had all 4 Oxygen sensors replaced and the car did great...after a few miles engine light came on again and its giving me the codes: P1187 (2) and P1193 (2) again!
It strange ALL four are listed this time...
Could it be a fuse?
If its a fuse...: which fuse is it ?????

Thank you

 

Satellite fuse box 1, F3 - 20A. Fuse is for the heaters, ECM, MFU, and ignition coils. Did you use dielectric grease in the O2 connectors?

 

sorry for not being specific..I have a 1998 Discovery 1 ..Fuse3 on Satellite 1 is "Engine Management" 10A ...would it be it?
..not sure about dielectric grease as I had them replaced by mechanic...does it need to applied on the tips of each Sensor ?
Thanks

 

Electrical connectors is where dielectric gets applied. The fuse info I posted is from the electrical circuit diagrams 97 - 99 1/2. I see in the 98 owners manual it's what you've listed. In that case who knows what fuse the heaters are using.

 

Well...the engine fuse in satellite 1 was a 20 instead of a 10 ..I replaced it and cleared the code...we'll see
Thanks

 

Cool, if that doesn't work the O2 electrical connectors are probably suspect - hence the dielectric grease. You have an "inferred" short circuit which means it isn't a "confirmed" short circuit. You have two connections between the O2 and the ECM. The O2 connector and the ECM large Molex connector. Either can have corrosion.

 

ok thanks