'94 Explorer problems with trouble codes

[jwb28207]

I'll try to be as detailed as possible due to desperation
I have a 94 explorer 4.0 with 141,000 miles that is my daily driver since last July.

Lately I've been noticing the idle started to seem like there was a miss and it started to get worse over a few days, so I simply did a tune up of filters, plugs, wires, coil, and added fuel treatment since it hadn't been done since i purchased the truck.

Seemed to work well for a few weeks and then I noticed worse and worse fuel mileage accompanied by a large decrease in power. Also there was really bad spark knock under heavy accelleration which I controlled with higher octane gas so far.

slowly the problem has been getting worse and worse to the point where The truck would cut off at idle and surge at high speeds. Then a few days ago the engine would start then shut off.

I have tried a few things to fix the problem including:
-Upper and lower intake gaskets and torqued bolts
-All new vacuum lines
-Canister purge solenoid (old one broke when pulling out vaccuum lines.)
-Cleaned MAF sensor and IAC as well as all other connections.
-ECT was replaced
-Relays for Fuel Pump and EEC
-Also fixed a hole in the intake hose

Truck ran like new for about 10 miles. cut it off and let it sit and now it is back to where it was before, except the spark knock is back.

The throttle body does not have a gasket right now due to being on back order.

Also I used an Actron OBD1 scanner
Continuous memory codes:
-172-Heated O2 sensor, lean condition, right side
-214-Cylinder Identification Circuit Failure
-332-EGR Valve opening not detected.
KOEO codes:
-335-EGR Sensor voltage out of range.

Fuel pressure @ 38 w/ vaccuum, 45 w/o vaccuum. Pressure stayed after 5 min.

Any and all input is highly appreciated. I have no other transportation at the time so if I missed anything please shoot a reply.
Thank you

 

[MrShorty]

I would start by resolving the KOEO 335 code. Because KOEO codes are set with the engine off, they almost have to be electrical faults. Inspect the DPFE sensor circuit. If it looks ok, then replace the DPFE sensor (a fairly common failure on these).

 

[x5050160]

Check the intake and pull of the egr valve. If its not plugged up then its the DPFE sensor. Change that out and that should take care of the EGR codes and maybe even the O2 sensor code. This is the procedure for fixing the 214 code:
Continuous Memory Diagnostic Trouble Code (DTC) 214 indicates an error has been detected in the Cylinder Identification (CID) input signal. The error could be due to a hard fault or an intermittent condition.

Possible causes:
Open or shorted harness.
Damaged Camshaft Position (CMP) /Crankshaft Position (CKP) sensor.
Damaged Ignition Control Module (ICM) .
Damaged Powertrain Control Module (PCM) .
Will engine start?
Yes -- Go to DR2. See: DR2 - Clear and Attempt to Re-Generate Code 214
No -- Go to Ignition Systems/ Electronic Ignition (EI) Diagnostics
DR2 - Clear and Attempt to Re-Generate Code 214
Notes
Clear continuous memory. See: Reading and Clearing Diagnostic Trouble Codes\Clearing Diagnostic Trouble Codes
Start engine.
Increase rpm to greater than 1500 rpm for 10 seconds. Repeat two times.
Key "OFF".
Rerun Key On Engine Running (KOER) Self-Test. See: Reading and Clearing Diagnostic Trouble Codes\Reading Diagnostic Trouble Codes\Quick Test Appendix (Detailed Testing Instructions)
Is Continuous Memory Diagnostic Trouble Code (DTC) 214 present?
Yes -- Go to DR3. See: DR3 - Check CID Circuit Continuity to PCM
No -- DTC 214 is intermittent. Go to DR20
DR20 - Check CID Wiring
Notes
Enter Engine Running Continuous Monitor Diagnostic Test Mode (DTM) . See: Reading and Clearing Diagnostic Trouble Codes\Reading Diagnostic Trouble Codes\Continuous Monitor Diagnostic Test Mode (Wiggle Test)
Observe Analog Volt/Ohm Meter (VOM) or STAR LED for a fault indication while performing the following:
CAUTION : While performing this test, do not touch any moving engine parts.
Shake, wiggle, bend the Camshaft Position (CMP) or Crankshaft Position (CKP) sensor wiring from the Powertrain Control Module (PCM) to as close as possible to the CMP or CKP sensor.
If possible, lightly tap on the CMP or CKP sensor/connector (to simulate road shock).
Is a fault indicated?
Yes -- Isolate fault and service as necessary. Clear continuous memory. See: Reading and Clearing Diagnostic Trouble Codes\Clearing Diagnostic Trouble Codes
Rerun quick test. See: Reading and Clearing Diagnostic Trouble Codes\Reading Diagnostic Trouble Codes\Quick Test Appendix (Detailed Testing Instructions)
No -- Key "OFF". For further diagnosis, go to Normal Scan Data Values . If an EEC-IV monitor box or Scan Tool is not available, go to DR21
DR21 - Road Test
Notes
The purpose of the road test is to identify an area of concern by monitoring certain controlled parameters while trying to recreate a driveability or MIL symptom.

NOTE: A basic working knowledge of the EEC-IV system is critical to effectively analyze road test data.

WARNING: This road test is a suggested but optional procedure. All applicable safety procedures and traffic laws must be followed. In order for a road test to be performed, it is required that another person accompany the driver. The accompanying person can make measurements, observe changes and record notes. If for some reason this test is not performed, return to Diagnostic Routines for other possible causes.

Prepare Vehicle For a Road Test
Breakout box installed, PCM connected.
Install fuel pressure gauge and MAP/BARO tester (optional).
Other materials needed: DVOM, pencil, paper, appropriate schematic/pin usage sheet.
Preliminary Power/Ground Checks
With the key "ON" and a DVOM referenced to the battery negative post, check the following signals for correct values.
POWERS:
KAPWR >10.5V (Pin 1)
VPWR >10.5V (Pins 37/57)
VREF 5 (+/-) 1V (Pin 26)

GROUNDS (all = 0 ±0.5V):
PWR GND (Pins 40/60)
SIG RTN (Pin 46)
IGN GND (Pin 16)

OPTIONAL GROUNDS:
HO2S GND (Pin 49)
CSE GND (Pin 20)
MAF RTN (Pin 9 or 15)

Obtaining Other information and Materials Before the Road Test
Refer to Normal Scan Data Values that most resembles the driveability or MIL symptom. Before the road test, perform the visual/mechanical checks that are listed. Next, list the EEC-IV sensors and actuators in the order given. These circuits and the CID signal(s) are the main circuits that will be monitored.
Refer to the proper Diagnostic Reference Value Sheet in Normal Scan Data Values . Although these charts were designed for use with the EEC-IV Monitor Box or Scan Tool, most of the values can be read using the breakout box and a DVOM (with the DVOM referenced to ground, all values in DCV units can be used; other values may also be helpful, ex., MAP Hz using the MAP/BARO tester).
After starting the engine for the road test, enter Engine Running Continuous Monitor Diagnostic Test Mode (DTM) . See: Reading and Clearing Diagnostic Trouble Codes\Reading Diagnostic Trouble Codes\Continuous Monitor Diagnostic Test Mode (Wiggle Test)
Drive the vehicle to create the conditions in which symptom occurs. If the Customer information Worksheet has been completed, this information may help in creating the symptom.
When the symptom occurs, the passenger should observe changes in listed Electronic Engine Controls (EEC) signals. information about the symptom, operating condition, value of the EEC signal or other notes should be recorded.
If the symptom cannot be duplicated verify that the EEC values are in the expected range.
Analyzing the Data
Once the road test is completed, the results should be analyzed to locate and service the fault which caused the symptom (if, for example, a Continuous Memory Diagnostic Trouble Code 214 is set again and the CID signal stayed within specification, the PCM would be suspect. If the signal went out of specification, the harness or sensor would be suspect).
If no problem is identified, return to Diagnostic Routines to continue with diagnostic procedures