93 Check Engine Light when on highway

So I just recently bought this 93' Grand Marquis, with about 129,000 miles on it. I noticed the check engine a couple of days later after I bought it and since then been having problems with it. Here is what has happened and what I've fixed.


Was running rough, took it in, short in fuel pump
Also changed the fuel filter before taking it in
Ran a little better but still was stalling and check engine light
Checked spark plugs, gapped too tight or lose (.040 to .060, a few correct .055)
Bought new plugs and wires, plan on installing tomorrow (6/20/2013)
Ran a lot smoother but eventually stalled again and CEL
Took it in again, they replaced the Throatle Position sensor, checked our spark plugs, and fixed a leak in the air intake. (the thing over the engine block connected to the air filter)
Don't know what to do, light still coming on and I am worried it will stall again.


Also, the CEL seems to come on when I go to Cruise Control right away, but I have driven without it and it still shows up.

I really didn't want to buy a project car and I hope it is an easy fix, but it probably will not be. Thanks in advance for any help you can give me :headshake

We changed the plugs and wires today, it seems to drop a little and we noticed it sputtering again. I am wondering if it is the IAC, but I do not know where that is located.

We just checked the IAC and it was 10 ohms (and really hard to reach too). I can't think of anything else to look at. It goes up and down whenever you are in park, reverse, or drive.

I got a OBD I reader from Amazon yesterday and we tried it out today.

KOEO
Codes
111 - O
157 - C (taken care of already from the previous repair)
158 - C (same as above)
332 - C [Insufficient EGR Flow Detected]
337 - C [EGR Sensor circuit above maximum]
634 - C [Manual Level Position sensor voltage higher or lower than expected] (we checked to see if it starts in D or R, but it doesn't. It also clicks when we shift gears so that is fine too)

KOER
Codes
111 - R

(No extra codes)
I am still wondering because I get that engine check light when I am on the highway.

I would replace the IAC and clean the EGR ports completely. Then disconnect the battery for about 30 mins to reset things. Some testers allow for the deletion of codes so you are not getting them back without a real issue. There is info, online, for cleaning the EGR ports (I believe "lincolnsonline" has a write-up with photos or the dealer would be glad to do it.). Usually you DO NOT need to replace the EGR but it should be looked at. Hope this helps!!

I would replace the IAC and clean the EGR ports completely. Then disconnect the battery for about 30 mins to reset things. Some testers allow for the deletion of codes so you are not getting them back without a real issue. There is info, online, for cleaning the EGR ports (I believe "lincolnsonline" has a write-up with photos or the dealer would be glad to do it.). Usually you DO NOT need to replace the EGR but it should be looked at. Hope this helps!!

Thanks! Finally got someone to respond. I am planning on checking the EGR sensor for the ohms (30-70). I will also look at the ports and clean them.

I do not think there is anything wrong with the IAC (we couldn't even reach it but we tested it and it was fine.)

testing components with an ohmmeter is not a valid test.clear codes and see which ones return.code readers are very limited.a cheap used snapon scan tool from ebay would be better choice.then you could do key on engine off and key on engine running tests that are decitated to ford only.I have bben doing diagnostics for 25 years.let me know what codes return.main driveability problem is stalling?correct?when does car stall?engine cold or hot.......while accelerating,deceleration,steady throttle,idle?

Here is a link that shows how to read and erase trouble codes for pre OBDII systems. There is a good possibility the EGR sensor is the issue from your codes. (the 332 and 337) The MLP code is probably an adjustment on the sensor on the side of the transmission. www.autozone.com also has some repair information that is free and supplied by Alldata.
http://troublecodes.net/Ford/ Post back with any other questions. Sorry, my computer was down for a few days.

testing components with an ohmmeter is not a valid test.clear codes and see which ones return.code readers are very limited.a cheap used snapon scan tool from ebay would be better choice.then you could do key on engine off and key on engine running tests that are decitated to ford only.I have bben doing diagnostics for 25 years.let me know what codes return.main driveability problem is stalling?correct?when does car stall?engine cold or hot.......while accelerating,deceleration,steady throttle,idle?

I have a good code reader. It caught the codes the guys at the dealership didn't get. The scanner I got is for Ford and Mercury only. I did do a KOEO and a KOER.

As for stalling, it is usually at night I notice it after work. I will leave, and at a long light, it will stall. Idle. Engine is hot.

Here is a link that shows how to read and erase trouble codes for pre OBDII systems. There is a good possibility the EGR sensor is the issue from your codes. (the 332 and 337) The MLP code is probably an adjustment on the sensor on the side of the transmission. www.autozone.com also has some repair information that is free and supplied by Alldata.
http://troublecodes.net/Ford/ Post back with any other questions. Sorry, my computer was down for a few days.

I did erase the codes. The scanner I bought allows it to do that and I saw 111 only after I finished clearing. Will check again.

Retried seeing the codes again after clearing them, got the following codes:

332 C
337 C
634 C (I am curious, could I be getting this one just because there is a problem with the scanner and it seems to happen when I turn on my air or have used it that day.)

We tried to fix the EGR (or clean it) but could not get it off. The bolt for the last hose connected to it was tricky and just wouldn't come off. We are probably taking it in for a diagnostics of the car and why it is doing this.

Since you have the 332 and 337, it is probably the EGR pressure sensor, not the valve. The 634 is probably due to the MLP on the side of the transmission either bad or out of adjustment.
I removed the 3 posts you had deleted.

PFE Sensor - MIL ON/DTC 332 Stored in MemoryArticle No.
96-25-9
12/02/96
^MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATION - DIAGNOSTIC TROUBLE CODE (DTC) 332 STORED IN MEMORY - WATER PRESENT IN PRESSURE FEEDBACK EGR (PFE) SENSOR
^LAMP - MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATION - DIAGNOSTIC TROUBLE CODE (DTC) 332 STORED IN MEMORY - WATER PRESENT IN PRESSURE FEEDBACK EGR (PFE) SENSOR
FORD:
1992-94 CROWN VICTORIA
LINCOLN-MERCURY:
1992-94 GRAND MARQUIS
ISSUE:
A Diagnostic Trouble Code (DTC) 332 and/or Malfunction Indicator Lamp (MIL) illumination may occur on some vehicles. This may be caused by a faulty Pressure Feedback EGR (PFE) sensor. Some vehicles may also show signs of water present in the PFE sensor or sensor port. This condition is a normal result of the combustion process and no action should be taken if the only concern is presence of water.
ACTION:
Perform normal diagnostics as outlined in the appropriate year Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual to determine if the PFE sensor needs replacing. If test results show the PFE sensor needs replacing, replace the PFE Sensor (F4AZ-9J433-AA).
PART NUMBER PART NAMEF4AZ-SJ433-AA Pressure Feedback EGR (PFE) Sensor
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage And Emissions Warranty Coverage
OPERATION DESCRIPTION TIME962509A Replace Pressure 0.3 Hr. Feedback EGR (PFE) Sensor
DEALER CODING CONDITIONBASIC PART NO. CODE 9J433 08
OASIS CODES: 204100, 206000, 698298

easy to diagnose egr flow problems with a good scan tool.

Update:

We took it in to a local shop, they said we had a vacuum line that was punctured. They checked and cleaned the EGR but it seems to run good. I guess I will see in a week when I test the codes.

Thanks guys. I hope this is the last of my problems.