Codes P0171 - PO174 with VCS off

Driving along and ck engine light comes on then 4L starts flashing as well as VCS OFF starts flashing. Codes are too lean bank 1 and too lean bank 2. I understand the codes but my question is what would cause the VSC and 4Llights to flash also. Codes erased and return after driving about 2 or 3 miles I wouldn't think the engine lean or rich would have anything to do with the four wheel drive. Thanks

 

Directly it does not. It is rather standard on many toyotas (and other makes) to have the overall system go into 'limp' mode whenever a significant error comes along like P0171.

It threw the code for a reason. Given the age there may be a very small crack developing on the intake 'hose' between the MAF and plenum. Only other cause would be injector issues. Luck.

 

Thanks for the info. I'll check that today.