1996 explorer code-but which sensor?

hey guys ive popped 3 codes out:

P1507- idle control
P1131/1132 fuel air metering
P0500 speed sensor A.

idle control is a cheap part.

**fuel air metering is about $272- but what are the chances its just a carbon build up and i clean it?

***Also- for the speed sensor A, which sensor is it?
there is one on the rear differential, one on the tranny (both cheap), but the expensive ones are on the front left and right hubs- anyone know how I could find out?

Thanks!
-Chris

The P1131 and P1132 is for the front sensor on the passenger side. Since you have both a rich and a lean code, I would suspect the sensor is bad. The O2 sensor does not cost what you stated. It should be way less than 100$. Purchase the O2 sensor for the vehicle. The P0500 is for the sensor on the transmission.

As Way2Old mentions, the P1131 and P1132 codes indicated the system is attempting to correct for both an overly lean condition and an overly rich condition on Bank 1. The service manual suggests checking the following items:

Possible causes:

Fuel system
-- Excessive fuel pressure.
-- Leaking fuel injector(s).
-- Leaking fuel pressure regulator.
-- Low fuel pressure or running out of fuel.
-- Contaminated fuel injector(s)
-- Vapor recovery system

Induction system
-- Air leaks after the MAF.
-- Vacuum leaks (vacuum lines and gaskets).
-- Restricted air inlet.
-- PCV system.
-- Improperly seated engine oil dipstick.

EGR System
-- Leaking gasket.
-- Stuck open EGR valve.
-- Leaking diaphragm.

Base engine
-- Oil overfill.
-- Cam timing.
-- Cylinder compression.
-- Exhaust leaks before or near the HO2Ss.

-Rod

replacing it would clear P1131/1132, but would it re trip the code immediately , or do you think it would pass inspection?

That answer can only be found by doing a long series of tests for that specific code. Rod has posted possible causes that need to be checked out. If the problem is in the wiring somewhere, the code would return. If it is in the sensor, it will fix it. In past experience, if a part will give both output codes going to opposite ends, it is the component. It can also be the PCM as a long shot.

p1131/1132 code says fuel air metering.

I was told i need a new mass airflow sensor, picked one up for $150.

but isnt the o2 sensor a different code? and how would i know if i needed upstream or downstream.

Consider troubleshooting with used sensors, because CASH for Clunkers gave us a graveyard of parts.

Profile the suspected sensors, see which one go's through more abuse.

The MAF will not give you the 1131 and 1132 code. It can be a factor in one or the other, but not both at the same time. Usually if both codes come up like that, it is the sensor, wiring, or the PCM>