Diagnostic codes dont make sense

[OrLackThereof]

I've been getting a Check Engine light on when I'm driving lately. At first, it seemed correlated to me running the car low on gas. However, the other day it did it with a half tank, and the light would not go out any time I put load on the engine. So, I went into Autozone and borrowed their EEC-IV code puller...

I did a KOEO test, and got this:
Code 11
Code 32
Code 11 I guess is a normal everything's ok code...but code 32..according to Autozone, doesn't exist. And I know how to read codes, I've done it before. It WAS a code 32.

I also did a KOER test, and got:
Code 41
Code 91

Both O2's reading fixed lean. Now, I'm running lots of mods, and have an AFPR that WAS set to 42 psi (w/ vacuum). I decided, however, to bump it to 45 psi to see what happened. Well, the car now runs PIG RICH and has ZERO power... Makes a big stink at idle....and a KOER test STILL reads both O2's as lean. This is definitely not correct. So, what could be causing my nonexistent codes, and false lean readings? I know the false lean could be fouled O2's....but, both of them, at the same time, when they have a MAX of 20,000 miles on them? I checked for vacuum leaks already, and I have none. My MAF is aftermarket and in good shape....I clean it regularly (the K&N filter's oil gets on it and fudges the signal up)

And, can anybody shed some light on the Code 32 deal? I'm lost here. I throw a check engine light, and then the computer gives me a code that doesnt exist... The computer says I'm always running lean.... I'm beginning to think the computer is just malfunctioning.

Thanks everyone. I'm on the verge of ripping it out and doing a carbed conversion. Arrrrr

 

[jrichker]

Code 41 or 91 - O2 indicates system lean. Look for a vacuum leak or failing O2 sensor.
The computer sees a lean mixture signal coming from the O2 sensors and tries to compensate by adding more fuel.

Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter.
The O2 sensor ground is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts

"When the mixture is lean, the exhaust gas has oxygen, about the same amount as the ambient air. So the sensor will generate less than .4 volt. Remember lean = less voltage.

" When the mixture is rich, there's less oxygen in the exhaust than in the ambient air , so voltage is generated between the two sides of the tip. The voltage is greater than .6 volt. Remember rich = more voltage.

Here's a tip: the newer the sensor, the more the voltage changes, swinging from as low as 0.1 volt to as much as 0.9 volt. As an oxygen sensor ages, the voltage changes get smaller and slower - the voltage change lags behind the change in exhaust gas oxygen.

Because the oxygen sensor generates its own voltage, never apply voltage and never measure resistance of the sensor circuit. To measure voltage signals, use an analog voltmeter with a high input impedance, at least 10 megohms. Remember, a digital voltmeter will average a changing voltage."
Charles O. Probst, Ford fuel Injection & Electronic Engine control

Code 32 - Code 32 - If the orange/white wire has Vref, (5 volts =/-.25 volt) then you have some wiring problems. Ohm the wiring back to the computer. Check for resistance between the brown/lt green wire on the EGR sensor and pin 27 on the computer: you should have less than 1 ohm. Repeat the process for the orange/white wire and pin 26. Do it again between the black/white wire and pin 46. In no case should you have more than 1 ohm. Remember that resistance checks are always done with the power off the circuit.

Voltage and resistance checks are good: Here’s an EGR test procedure I copied from cjones

to check the EGR valve:
bring the engine to normal temp.
connect a vacuum pump to the EGR Valve
apply 5 in vacuum to the valve.
if engine stumbled or died then EGR Valve and passage(there is a passageway through the heads and intake) are good.
if engine did NOT stumble or die then either the EGR Valve is bad and/or the passage is blocked.
if engine stumbled, connect vacuum gauge to the hose coming off of the EGR Valve
snap throttle to 2500 RPM’s (remember snap the throttle don't hold it there).
did the vacuum gauge show about 5 in vacuum?

if not, check for manifold vacuum at the EGR vacuum valve.
if you have manifold vacuum then connect vacuum gauge to the EGR valve side of the vacuum valve and snap throttle to 2500 RPM’s.
should read about 5 in vacuum
End of cjones's test.

Fails to provide proper vacuum, check vacuum feed lines for cracks & damage. If he vacuum lines are good, check the electrical wiring to the EVR. If the EVR electrical wiring is good, look for 12 volts on the red wire for the EVR. If the 12 volts is good, look for a varying voltage on the dark green wire on the EVR. Case of last resort, replace the EVR and then the computer

 

[OrLackThereof]

Thanks for the tips man. Unfortunately, I'm electrically retarded and am terrible with a multimeter...not to mention I lost my probe leads to it so I'm stuck with alligator clips...

I've checked for vacuum leaks repeatedly and find none, although my engine only pulls about 12 HG's of vacuum at an idle.

EGR valve is less than a year old---my old one was jammed up and never opened.

Do you know how long it typically takes O2's to foul out? Like I mentioned...these have less than 20,000 miles...probably about 15,000 on them. They're Bosch OEM replacements.....damn things were $40 each.

I have exhaust leaks as well, that might play a part in the O2s getting extra oxygen...however, I'm pretty sure all of the exhaust leaks are behind the O2's. But I'm going to have to check the collectors out...

By the way....what is the EVR? Electronic Voltage Regulator or something like that?

 

[jrichker]

EVR is the Electronic Vacuum Regulator for the EGR: it is located on the rear of the passenger side wheel well. The computer sends a pulse to turn the regulator on & off to control the vacuum. The regulator opens a vent to the outside to decrease the vacuum in the regulated part of the vacuum circuit. Computer on pulse opens the vent, dropping the vacuum. Computer off pulse closes the vent to let the vacuum remain at the current level.

 

[FoxChasis]

Fault code 32 means the EVP sensor's voltage is below closed limit.

Remove the EGR valve from the vehicle, clean it thoroughly, and reinstall it. Check all vacuum lines and hoses in the EGR circuit and replace or repair as necessary. Re-check EEC codes.

The EGR valve may have to be replaced (cleaning sometimes works, but sometimes not). Proper test equipment (vacuum pump and VOM) are required to diagnose the EGR circuit.

 

[jrichker]

Fault code 32 means the EVP sensor's voltage is below closed limit.

That's what happens when the Vref (orange/white wire with 5 volts on it) goes away. The closed voltage drops below the low limit because there is no 5 volts across the variable resistor that is in the EGR sensor.