Hello everyone

Hopefully somebody can help me out with this. I own a 1996 Disovery and can't get it to pass emmissions. The OBD diagnostics say that there are problems with the O2 sensor heater circuit open upstream, and O2 sensor heater high resistance upstream. I have already reeplaced 2 o2 sensors on the passenger side of the vehicle, but these codes keep coming up. I am hoping someone out there could give me some solid hints on what it actually needs to pass inspection.

Thanks a lot

 

How many miles on your truck?
What are the exact fault codes?
You must replace all 4 02's when doing it.
You will probably find you have either some bad connections or issues with the 02 sensors wiring harness.

 

Thank you Mike, there are 160000 miles on the truck, the codes are p1185 and p1188. Why do all four have to be replaced if two of them were still good. Is it possible that the O2 sensors are no the whole problem and that the problem could have to do with the air/fuel mixture process, like air flow sensors or a bad fuel pump? Plus how can I tell if my cat is toast, I see a lot black soot at the end of my tail pipe. I smell fuel when driving around like it is burning it way to rich, if that helps.

Plus my SRS light won't stop flashing, ever had to fix that before?

Thanks

 

I understand you concern about your 02's, but bottom line after they hit 100K, they are not giving your engine the full range of their ability, hence you are getting less performance and worse gas mileage compared to a new set.
Change them and see. By the way, it is not your fuel pump, and as for your SRS, I would go have some check it for codes cause it has failed on you, as the fault codes will show.

 

Thanks, besides the o2 sensors what would cause the disco to have a rich air/fuel mixture, becasue the tailpipe is very sooty and is running very rich.

 

Bad readings from the 02's to the ECU, most likely.
What octane gas are you running?
I would suggest high test, you will get better mileage and less change of a carbon build up.
When you get this taken care of consider an engine flush then an induction cleaning to get rid of alot of old sludge and carbon.