HELP with engine codes

[deftsound]

hey guys,
i just got one of those actron code scanner things for my car because ive had problems with my engine idling too high and getting really bad mileage. Well, i did the engine running test and i got the following codes: 13: Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too high) 41: System lean - Fuel control 91:System running lean - Fuel control 34: EVP - EGR did not respond properly during test - EVP

I also did the engine off key on test and got these codes: 34: EVR - EVP sensor is/was high - EVR (O,R,M) PFE - PFE sensor is/was out of range - PFE
96: Fuel pump monitor circuit shows no power - Power / Fuel Pump Circuits

Lately, ive been getting really bad mileage, around 13 miles in town, and my car is almost completely stock so i know i should be getting a lot better, I have replaced my oxygen sensor so i know thats not the problem, i also replaced my intake gaskets not long ago and i may have miswired some of vacuum hoses. Tell me what you guys think as far as what i need to do, thanks

 

[deftsound]

by the way i forgot to mention its been running hot, around 200-230 range, i dont have a fan shroud at the moment but i just bought one and should have it shortly, and i live in south texas but regardless i should be running about 180

 

[jrichker]

Code 34 EGR voltage above closed limit - Failed sensor, bad or missing signal ground, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the EGR valve by mouth. If you can, replace the EGR valve ($85-$95).

If the blow by test passes, and you have replaced the sensor, then you have electrical ground problems. Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same wire on the TPS. It should be less than 1 ohm. Next check the resistance between the black/white wire and the negative battery post. It should be less than 1 ohm.


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.

The following is a Quote from Charles O. Probst, Ford fuel Injection & Electronic Engine control:
"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 400 Millivolts. 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 600 millivolts. 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." End Quote

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

Code 96 – KOEO- Fuel pump monitor circuit shows no power - Power / Fuel Pump Circuits
(Stored Memory code - Service 87 code first if present) Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits
Look for power at the fuel pump - the fuel pump has a connector at the rear of the car with a pink/black wire and a black wire that goes to the fuel pump. The pink/black wire should be hot when jumpered to the test position. . To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. http://www.mustangworks.com/articles/electronics/eec-iv_codes.html for a description of the test connector. it. No voltage when jumpered, check the fuel pump relay and fuse links.

 

[deftsound]

hey thanks man your the greatest I guess this explains my bad gas mileage, ive always had problems with vacuum leaks, maybe ill just rewire the whole thing, thanks again i really appreciate!

 

[deftsound]

hey i know this is a newb question but, where is the egr valve and how do i replace, also where is the fuel pressure regulator and how do i replace that?

 

[deftsound]

HAH! im the smartest man alive haha, ok so after i found the egr valve i noticed the vacuum hose was not plugged in, it was capped off, so i plugged it back in and it started idling real rough like it had some radical cam or something, so now i know its the egr valve thats causing my problems! unfortunately i burnt the ***** out of my fingers trying to take the damn thing off so i gotta wait for it to cool down before i can take it off and clean it, if it doesnt work ill just buy a new one, as far as it running lean maybe this is why, i hope