2001 Disco II... lack of power under load, bogging when throttle applied. Removed and cleaned MAF (with MAF cleaner) and IAC, no change.
I going to replace the MAF as it's probably due for a change but regarding the O2 sensors... if I'm on a budget and I need to replace in stages, which most likely the culprit, before or after the catalyst?
I guess the Po 174 code is too lean (bank 2)
Anything else might cause it?
Anyone with any opinions on the Allmakes MAF sensor Lucky8 sells? If it lasts me a year I'll be happy.
Any advice or tips appreciated.

UPDATE: The MAF from Allmakes that mollusc shipped me did the trick. Night and day smoothness. No more bogging or lack of power under load. I have no idea what the average lifespan of a MAF sensor is but I hope it's at least a year for an Allmakes! Thanks mollusc!

7/15 UPDATE: Allmakes MAF died yesterday, time for a genuine Bosch.

 

I have a spare Allmakes MAF that you can have. Some people say they work okay; others don't have any luck with them. I'm in the latter category so I had to replace my replacement with a genuine Bosch.

 

Thanks for the offer! I hope it's the MAF, just trying to figure out if I should swap the pre or post O2 sensors if that doesn't help.
No vacuum leaks found.
Thanks again!

 

If you have a code reader, check the voltages of the O2 sensors on that right bank. A MAF issue will usually throw more than just that code, especially if it's not making power and bogging under throttle. Upstream O2 is more likely

 

P0174 (and its good friend P0171) are often caused by vacuum leaks. In some of the more difficult to diagnose cases it's been found to be due to leaky fuel injector O-rings.

 

Leaking fuel injector o-rings caused P0174 on my rig. It is a good excuse to get in there, and replace all the parts as you go along.

Troubleshooting sequence:

1. Get UltraGauge and setup a page with STFT and LTFT for both banks.
2. Drive, monitor the conditions that cause positive STFT to spike (> 20). In my case, hard braking cause spike in STFT in bank 2
3. If both banks spike at the same time, you have an issue upstream from fuel injectors, e.g., MAF
4. If one banks spikes and the other does not, your issue is more likely to be due to vacuum leaks around fuel injectors, e.g., bad O-rings

To test for vacuum leaks around the fuel injectors, use the brake fluid test--spray the fluid around the injector when the car is on. If the RPMs spike, you've got your answer.