P0171 P0174: Lean codes

So I just setup to take my truck in for maintenance which is 100 miles from me and the Toyota service advisor just called to tell me NOT to drive the truck because Service Connect is reporting lean codes. This is a supercharged Tundra with the 2650 Magnuson.

Question? Is it safe to drive with the P0171 P0174 lean codes? I have no check engine light or anything else going on. Truck drives fine.

 

There should be a CEL if you have lean codes unless they’re pending and not active. Do you have an HPtuners MPVI to data log? I’d say there’s 3 likely causes if there are in fact lean codes, especially on both banks.
1. Vaccum leak on the intake post MAF (check all of your connections on the intake)
2. A bad tune (is this the stock magnuson tune?)
3. Contaminated gas, I’ve actually had this issue once with bad gas combined with towing giving me lean codes.

Paging the wizard @snivilous

 

Thanks:

The codes are in the Permanent section in TIS Techstream. No CEL. I am taking into the dealership where I installed the SC, that's the reason I asked if I can drive it. The foreman told me to drive it normally if nothing weird.
For #2, it is the stock Magnuson tune. I run with it for about 6000 miles now, no problem. In stall of the SC was July last year at 5000 miles.
For#3 It could, I always get the Costco since 93 is cheaper there.

 

I think it would be fine to drive, just take it easy and don’t get into boost.

 

Thanks and yes I plan not to.

 

I'm not expert, but that's weird there's no CEL. If it was me I would just keep driving it like normal, the truck hasn't told you there's anything wrong so I'd have a hard time trusting some random external source that it's lean. Maybe drive it with caution like Silver said, but the lean codes can blow if any little part of the whole operating range is a little outside of what the truck wants to compensate for. Meaning you could be slightly lean at idle or at WOT. Usually a lean or rich code is for one specific time, it's not like it's critically lean in the whole operating range. If there's a way to datalog I would try to see what's up, you don't need tuning softwate to do that either, any scanning item (like your phone) can be used, just watch the long term fuel trims and see if they are exceeding 20% anywhere.

 

Thanks. I do have the OBD Fusion app plugged in at all time. I wonder if there is a PID for that to monitor fuel trim in real time as you suggested.

 

If the code is stored but not active you should be okay, emissions related codes stay there for legal reasons I believe but if the CEL is not on then I don't believe they are actually currently happening and are cleared.