My original thread can be found here (https://landroverforums.com/forum/di...-check-110332/)
Basically I had a P0300 and P1316, both were cleared with new plugs and wires. Codes were reset using OBDII and have stayed away. On the original diagnosis, I also had a this P1179 that I was hoping would go away by switching over to premium unleaded. This code was also cleared using the OBDII and stayed away for 3 or 4 days (not sure how many miles), however It just popped back up again this evening.
As my previous post explains, these is a brand new car to us and has been meticulously maintained. I have all the records dating back to the original purchase.
The MAF looks brand spanking new, although I havent looked/found when it was actually replaced. So excluding that, where would you start? O2 sensor?

 

vacuum leak? there should be a vacuum diagram on a sticker in the engine compartment. Check out all the lines, and try to propane/starting fluid trick to see if you can get the idle to change.

 

What is the definition of P1179?

 

Long term fuel trim too rich, banks 1&2 (MAF). Needs to be >+24% to set off that DTC.

Page 33 of the obd_gems manual.

 

So, bad vacuum leak (e.g. from canister purge valve open), or very low fuel pressure (bad pump/filter and/or regulator), or a bunch of plugged injectors (that would be a fancy trick).

Are the O2 trends still modulating? What is your mpg? Does trim change at idle compared to on the road?

 

Looks like the MAF sensor is only a few months old (replaced in 8/21). I called the shop that did the work and the guy said he would try with another brand of MAF sensor as he was skeptical of the one he put in. Something about not having access to parts due to their remote location and lack of smog restrictions on older cars in their state. He also said I may just want to clear the code, use the OBD to check for readiness and then limp it back to the smog place and try again.

 

IM going to check the hoses this afternoon for leaks. How do i check 02 modulation?

 

To check O2 sensors, I use the Torque App on my tablet and a bluetooth OBD plug-in. Sounds like you haven't tried this before.

What scanner do you use? Most have a way to view real time signals from the O2 sensors. There's a ton of info on YouTube.

 

Im using a Creader 3001 OBD2 scanner.

 

It looks like this P1179 code is gone again. CEL turned off on its own. Im gonna run it in today and get the smog (hopefully). The fact that this code has turned on off on off again, does that point anyone here to a likely cause for the next time it comes on? Ill still hook it up and see if i can get 02 readings just for fun through