1998 Ford Taurus Theft Light and Codes

FORD TAURUS
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HAIRCUT
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I have a 1998 ford Taurus with a 3.0 six cylinder 130,000 miles. I changed the egr valve around 6000 miles back and the check engine light has stayed on. Therefore, per advice from local parts store, I did a general tune up and the light has not been off since. Now at times when I start the car and the theft light flashes at a high rate of speed and seem to be idling at a high rate around 2000 rpm. Then at times, it tries to stall out if it has to idle for to long... do you have any good advice it would really be grateful. Haircut
Feb 28, 2007 at 12:23 PM
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TAURUSWHEEL
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Why did you change the egr valve??? Testing proved it to be bad??? Get a scan done again and post the code numbers,, as for the theft light, do you have the active or passive alarm system??? o you have the key with the chip in it??? The flashing theft light could be a code sequence, post back.., I would suggest buying a code scanner, they can be had for less then a 100 bucks, a great investment.
Feb 28, 2007 at 2:59 PM
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HAIRCUT
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The reason I changed the egr valve was a local mechanic told me the code come up that it was bad.
The key I have is one of the thick ones that has a chip in it; the car will not run without it. The dealership said when I bought the car that it shut the system down without it. I asked which system it deactivated, one time he said the fuel system, then he said ignition system so I am not sure which one it kills but it will not run without the key.
As for the codes, I stopped and got a code reader from a friend and when I checked the codes, they displayed as, 401, 171, and 174.
i watched the theft light and it seams to be flashing five times then pauses then flashes six times.
What dose this mean and what would you do to fix it?
I would really be very greatful for any help you can give me. Thanks haircut
Mar 7, 2007 at 11:55 AM
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TAURUSWHEEL
  • ✓Experienced Mechanic
  • 718 POSTS
i believe the 0401 code relates to a flow issue in the egr system, offhand without looking, this is usually, not always, but most of the time it will be the dpfe sensor, which measures the flow thru the egr, it is a small plastic, sometimes gray in color, sensor with a couple of small rubber hoses, vacuum type, attached to it.. this part is a known failure part... as for the other 2 codes, check the sticky post above that has the two code numbers posted in the header, this issue may have to be traced down by a knowledgeable shop, though thyere are some things you can check, make sure all vacuum and pvc hoses are hooked up and in good shape, includes the dpfe sensor hoses.. you can clean your maf sensor, that may help.. the pats alarm system with the theft light flashing, it indicates something is awry in the system, the dealer may have to look at that issue, did you get any codes for the pats system???
Mar 7, 2007 at 3:19 PM

Suggested Repair

Rescan and address codes 0401, 0171, and 0174. For the EGR flow code, inspect the DPFE sensor and its small vacuum hoses, a common failure, and confirm all vacuum and PCV hoses are connected and sound. Clean the MAF sensor. Have a dealer diagnose the PATS theft-light flash pattern and any related high idle or stalling.

Conversation Summary

A 1998 Ford Taurus owner reported a persistent check-engine light after an EGR valve replacement, intermittent rapid theft-light flashing with about 2000 rpm idle, and stalling during long idle. Codes read were 401, 171, and 174, and the theft light flashed five times, paused, then six times. The car uses a chipped key and will not run without it. The expert said 0401 usually points to EGR flow, often a failed DPFE sensor or its hoses, advised checking vacuum and PCV hoses and cleaning the MAF, and suggested dealer diagnosis of the PATS theft system.

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