Hello-
I recently picked up an '01 with 138K miles. At 120k, previous owner did a ton of work with keeping everything in good shape, but when he replaced the o2 sensors, he only did 3 of the 4 (driver's side pre-cat not done).

Since it is throwing 0171 and 0174 for both banks, could that be caused by one o2 sensor? Or should I be thinking the MAF?

Also, I've seen some posts on these codes reference a vacuum leak, but I couldn't find a diagram of those tubes in RAVE, can anyone tell me how to diagnose?

 

Carb cleaner is your friend, while idling spray lightly at suspect spots around intake gaskets, PCV hoses, any joint that is down stream from the MAF. The MAF meters the air going by, and when un-metered air sneaks in later the ECU can't compensate enough.

Don't clean MAF with carb cleaner, use a made for MAF spray and only do it when key has not been in ignition for 8 hours, just turning to position 2 warms up the MAF inside.

 

I would rule out a vacuum leak first, since it is way cheaper to fix than a MAF/O2 sensor.

Has the truck been throwing these codes since you got it?

If you decide to go the vacuum leak route, this post has some good info:
https://landroverforums.com/forum/di...s-cigar-54235/