Need help with engine error codes on 99 boxster

[Pianohawk]

I have the following engine error P-codes:

P0102 (Mass air flow sensor, short to ground/below lower limit/ lean mixture threshold)

P1124 (fuel pump relay output stage, short to ground/below lower limit/lean mixture)

P1126 (oxygen sensing adaptation, lower load range, cyl. 1-3, short to B+/above upper limit/ rich mixture threshold.)

I would be immensely grateful to anyone who has ideas on where to start. Thank you soooo much!

Colby

[BYprodriver]

Only input I can offer is I have heard the fuel pump relays can go bad & a new one is $15 or less. It is easy to replace under the dash drivers side. Pull off the fuse panel cover & you should have a diagram there. I had to get a Bently manual since my diagram was missing. That may be the only problem.

[landrovered]

Lean codes can be caused by vacuum leaks , secondary air injection faults and exhaust manifold leaks.

Lean limit suggests that you have some oxygen (air) getting into the system and the pre-cat O2 is trying to compensate and it is running into the limit because the O2 is coming from the atmosphere and not from the combustion process.

That is where I would start.

[landrovered]

It would appear that HUALE768 is an even smarter spam bot that is now combining posts in a thread to be harder to spot. Amazing what hackers can come up with.

[Pianohawk]

Thank you for your replies! I'm going to try and clean out the MAF sensor this week and cheek the fuel relays as you suggested.