Guys,

These codes popped up, I cleeared them, They came right back, drove it two more weeks, cleared them ,added Seafoam 1/2 can to gas tank & 1/2 to crankcase, put in another tank of gas. It has not repeated yet.

I know there can be several random causes, What I would like to know from someone who is real knowledgeable about these, what inputs or outputs can I measure with my meter next time so I can try to see what may be most likely cause?

 

I'm next to positive that 1148 is what my truck was throwing when the upstream o2 se sensor went (driver side). My guess is that 1146 is probably then related to you running too rich or too lean because of the bad sensor.

 

That is the kind of info I was looking for, thanks for the answer. I guess I amm way overdue for O2's even though those are the only codes I am getting (no direct O2 codes yet).

Is there a measurement I can make or should I just plan on new O2's as part of next planned purchase?

 

I don't know what you could look at as far as determining if they've failed or not. I just took a leap of faith because the search I did indicated that I had a bad air fuel mixture and people told me it was due to bad upstream sensors. I went cheap and got the generics and ill be back under there at some point replacing them this summer because they're crap compared to the OEM's. If you can afford them (they're pricey) at least get the OEM's for the up stream.

 

The Land Rover Code list I have doesn't even list those.
A search of Google shows them meaning different things for different cars.

P1146
Land Rover: Lambda trim post-catalyst bank 1.Short circuit to V Batt

P1148
Land Rover: Lambda trim post-catalyst bank 1.Short circuit to ground

If those are correct I'd check the wiring to make sure it's not damaged. If it's good then go ahead and replace your sensors since you say you're past due.
Amazon has been the cheapest on them for a while.

I think I had an 1148 last year and replacing the sensor fixed it.

 

Tom, thanks for the details, so just to be clear, you are referring to the O2 sensor wiring?

I will get a pair on order ASAP.