1998 Ford Expedition Misfire

Tiny
GEAUXTIGERS
  • MEMBER
  • 1998 FORD EXPEDITION
  • V8
  • 2WD
  • AUTOMATIC
  • 145,000 MILES
The check engine light in my 1998 Ford Expedition, 5.4L engine, came on. The diagnosis was a restricted EGR flow. A mechanic friend suggested I just clean the ports connected to the EGR valve. Did that, had the check engine light reset and within 10 miles, it came back on. I then replaced the EGR valve and the DPFE sensor, again cleaned out all the connecting ports for carbon buildup. Check engine codes now say, mixture too lean in bank 1 and bank 2 and misfire in cylinder 1. I am going to change spark plugs and coils this weekend, but not sure that will solve all the problems.

My question, is this more likely a vacuum hose problem, given the lean mixture codes? If so, which hoses should I look at and what should I look for?The vehicle will sputter upon acceleration, but then respond normally. It idles rough and will sputter while cruising. It also has a terrible vibration at around 50 miles an hour. Any advice will be appreciated.
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Thursday, December 27th, 2007 AT 10:24 PM

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Tiny
BMRFIXIT
  • EXPERT
[quote="geauxtigers"]Engine problem
1998 Ford Expedition V8 Two Wheel Drive Automatic 145000 miles

The check engine light in my 1998 Ford Expedition, 5.4L engine, came on. The diagnosis was a restricted EGR flow. A mechanic friend suggested I just clean the ports connected to the EGR valve. Did that, had the check engine light reset and within 10 miles, it came back on. I then replaced the EGR valve and the DPFE sensor, again cleaned out all the connecting ports for carbon buildup. Check engine codes now say, mixture too lean in bank 1 and bank 2 and misfire in cylinder 1. I am going to change spark plugs and coils this weekend, but not sure that will solve all the problems.

My question, is this more likely a vacuum hose problem, given the lean mixture codes? If so, which hoses should I look at and what should I look for?The vehicle will sputter upon acceleration, but then respond normally. It idles rough and will sputter while cruising. It also has a terrible vibration at around 50 miles an hour. Any advice will be appreciated.[/Quote

the EGR can be a vacuum leak by it self.
Make sure egr valve is closing and working pro
also if you have not had a tune up you should start
by at least changing the plugs
check around the manifold for a vacuum leak
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Thursday, December 27th, 2007 AT 10:34 PM

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