My 03 Disco is throwing maf no activity and both upsteam o2's no activity codes. I checked the fuse because they are on the same one (F2 i believe) it is intact. I then bought new o2's and a maf. After installing maf i reset the codes and still had no activity. Is there a relay or harness known to cause this or what? All wires seem to be intact.

p.s. I am a new member so take it easy on me.

 

Do you have correct voltage at both the oxygen sensor and the maf. Does it stall on you? I have seen the back part of the wiring around the head get pinched while doing a head job causing issues.

 

Im relearning to use a multi meter since buying my Rover. It does have 12 volts to the maf i haven't yet checked the o2 voltage. At some point before i bought it things got pretty toasty around the fuse box as there is some melted plastic on the box cover. Make me wonder if the hareness next to the fuse box was damaged internally.

It stalls about once a week and generally runs ok. Four weeks ago i took it on a 1500 mile trip and averaged 16 miles per gallon. Now however it seems to be running much more sluggish and the mileage is down to about 10. I probably plugged up my cats running that far while running rich.

thank you for your responses

 

pull the fusebox and take a look for rotted wiring. Seen a few issues for other things but its possible maybe something is going on.