P1148 Code

[daroutt]

Can anyone provide any help on just what this code means and what it takes to fix it. First time it has come up. Was getting error codes that indicated both after cat O2 sensors were bad. Replaced both and the codes did not come back. But know this one has appeared and no help in either the Haynes or Chilton manuals on just what it means. Thanks

[nheitz]

It's for the forward right side O2 sensor. I'm not sure if it was the same for the QX4, but the PF had a TSB that said to change the bad O2 sensor & reflash the ECM. The problem was that condensation built up in the exhaust when not running. The O2 sensors fired up soon after ignition & they were shorting out from this condensation. The ECM flash makes them delay before they turn on to burn off the condensation.

[daroutt]

Thanks for the fast comeback. One other question. How do you flash the ECM? Is this a dealer only task or can I do it myself?

[nheitz]

It's dealer only unless you have the Consult II... yeah, you don't have that. Dealer only. But, don't let a dealer rape you on charges. It literally involves them hooking up under the dash & downloading the update. But it is worth it so you don't continue to fry the O2 sensors.

[daroutt]

Thanks again for the help. Since you sound like one who knows there way around these models, I need to ask another question. When I replaced the O2 sensors, I had to use O2 sensors for a 2000 Pathfinder built before Sept. 2000. I found this out after having the NAPA people order in 4 different sensors. I finally got a parts guy at NAPA that knew enough to look at the Pathfinder. My question is, I was getting a P0171 Bank 1 too lean error code. He suggested cleaning the MAF which I did. The P0171 went away but now I get a P0174 bank 2 too lean. Is the MAF on the fritz or is this a ECM reprogram item too.

[nheitz]

Ok, somebody else chime in here. I only knew about the O2 sensors because I've been through it. If you don't get answers I would post that as another topic.