Ok I have an 87 BII 2.9L 5 speed 4x4. Code 32 (erratic or valve position sensor to low) The truck runs great and gets about 24 mpg. I know I shouldn't complain but I don't want any codes showing up in the computer.

I have replaced the EGR valve with a new one. No change after clearing codes. There is a sensor mounted the the right side inner fender that has to hard plastic lines that connect to the EGR and engine. I'm guessing this is the sensor that control EGR function but I'm guessing. I'm hoping this may be the cause for the code.

Anyone know the name of this sensor? Has anyone had this problem?

 

Is located on the EGR. There should be a black plastic device with an electrical plug on the EGR.
Did the new EGR come with this part attached already?
AL.

 

No my EGR has no electrical attachments. The old one didn't either. I'll take a picture tomorrow and post it so you can see what I'm talking about.

 

That sensor is called the EVP sensor (exhaust valve position sensor). On the 2.9 litre the EGR valve is a ported unit not an electronic one like on the 2.8 litre or the 4cyl. The EVP is located on the passenger side inner fender. It will have a hard plastic line leading from the EGR valve to it and other lines leading to/from the vacuum reservoir in the air cleaner housing.

I hope you cleaned EGR port in the upper intake when you changed the EGR valve. The port has a 90 degree bend in it where the exhaust enters the intake manifold and over time cokes up with exhaust crud. You need to use some oxygen sensor safe carb cleaner and a drill bit to chip away at the crap in there. I cleaned mine out and it was completely plugged so the EGR was not functioning at all, new valve or not.

Good luck

 

The '86 and '87 2.9 use a pressure feedback EGR system. The basic components are:
EGR valve
Pressure Feedback EGR (PFE) sensor. Attaches to the EGR valve with a short vacuum line and is usually bolted to the throttle body/upper intake (unless your bracket is broken like mine). At the parts store, this part goes by a variety of names, such as EGR pressure sensor, EGR position sensor, and so on.
EGR Vacuum Regulator (EVR) solenoid. This is the one attached to the passenger fender.
EEC-IV computer. Monitors PFE signal output and controls EGR valve opening/closing via the EVR solenoid.
And, of course, various wires and vacuum hoses to connect it all together.

Basic operation: Computer monitors PFE signal. When the PFE signal goes above a given value, the computer applies a pulse-width-modulated signal to the EVR solenoid to apply vacuum to the EGR valve and open the valve. This continues in a feedback loop where the computer attempts to keep the PFE signal at a given valve by varying the modulation applied to the EVR solenoid.

Diagnosis of a 32 code best begins by identifying whether it is a KOEO 32, a CM 32, or a KOER 32 (or some/all of the above). SOP is to start with KOEO codes, because they almost always represent electrical faults. To diagnose a KOEO 32, one would focus on the PFE sensor and circuit. KOER 32/CM 32 (KOEO 11) introduces several other possible causes.

 

It's a KOEO code 32.

 

Because KOEO codes are set with the engine not running, they are almost always electrical faults. Focus your diagnosis on the wiring between the EEC-IV computer and the PFE sensor and the PFE sensor itself.