03 Eddie Bauer Performance Issues

[Brian Beckers]

Vehicle: 2003 Eddie Bauer, 5.4L Triton. 210,000 miles.

Issue: After vehicle has warmed up, the engine runs rough. Intermittent stutters. Poor performance under load. At times, lack of power under acceleration. Very poor fuel mileage. Average in-town MPG has dropped from 13 to 8. No check engine light and no codes at all (active/pending/historical).

What's been done: Fuel and air filters changed about 5k miles ago. New plugs last summer, probably around 10k ago. Late winter/early spring, developed a cooling leak above cyl 3 & 4. Leak fixed and the COPs and plugs on those 2 cylinders were replaced. About 3k ago, I had an odd code that ended up being a bad EGR Pressure Feedback Sensor. Replaced sensor and both connecting hoses. I've checked all the other hoses for cracks and only found one which I replaced (breather tube between throttle body and PCV valve).

Per another forum, performed a vacuum test to eliminate exhaust blockage. The test seems to indicate no exhaust obstructions or bad cats. EDIT: I am not 100% confident that this test fully eliminates a bad cat issue...

I don't have a lot of $ to just randomly throw at parts. This is my daily driver so I also can't have it sitting in the garage torn apart for days on end.

What tests can I perform that do not require any specialty test equipment? All I really have for test equipment is a vacuum gage and multimeter.

Please help!

 

[1955moose]

If you suspect a bad cat or 2, you can have an exaust shop check for usually free or low cost. With a vacuum gauge, hook it up, if your exaust is clogged, it will go from 18 inches and start to drop towards zero. As far as a clear egr system, a pump type vacuum gauge you can borrow from the parts store, you pump up while motors running warm, engine will stumble and try to die if passage is clear. You can also check egr valve with motor off. Same thing pump up, see if gauge holds.

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[StreetCreeper]

Vehicle: 2003 Eddie Bauer, 5.4L Triton. 210,000 miles.

Issue: After vehicle has warmed up, the engine runs rough. Intermittent stutters. Poor performance under load. At times, lack of power under acceleration. Very poor fuel mileage. Average in-town MPG has dropped from 13 to 8. No check engine light and no codes at all (active/pending/historical).

What's been done: Fuel and air filters changed about 5k miles ago. New plugs last summer, probably around 10k ago. Late winter/early spring, developed a cooling leak above cyl 3 & 4. Leak fixed and the COPs and plugs on those 2 cylinders were replaced. About 3k ago, I had an odd code that ended up being a bad EGR Pressure Feedback Sensor. Replaced sensor and both connecting hoses. I've checked all the other hoses for cracks and only found one which I replaced (breather tube between throttle body and PCV valve).

Per another forum, performed a vacuum test to eliminate exhaust blockage. The test seems to indicate no exhaust obstructions or bad cats. EDIT: I am not 100% confident that this test fully eliminates a bad cat issue...

I don't have a lot of $ to just randomly throw at parts. This is my daily driver so I also can't have it sitting in the garage torn apart for days on end.

What tests can I perform that do not require any specialty test equipment? All I really have for test equipment is a vacuum gage and multimeter.

Please help!

You say you replaced the egr feedback sensor, but did you replace it with OEM or just some parts store junk? Was the original sensor bad or was it the hoses that were cracked? We’re talking the same sensor right; the differential pressure sensor with two hoses?

 

[Brian Beckers]

If you suspect a bad cat or 2, you can have an exaust shop check for usually free or low cost. With a vacuum gauge, hook it up, if your exaust is clogged, it will go from 18 inches and start to drop towards zero. As far as a clear egr system, a pump type vacuum gauge you can borrow from the parts store, you pump up while motors running warm, engine will stumble and try to die if passage is clear. You can also check egr valve with motor off. Same thing pump up, see if gauge holds.

Sent from my N9131 using Tapatalk

That's exactly the vacuum test that I used to test the cats.
I don't think it's the EGR valve, but I can check if that's recommended.

 

[1955moose]

I would. When your chasing a problem, you don't want to skip steps.

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[Brian Beckers]

You say you replaced the egr feedback sensor, but did you replace it with OEM or just some parts store junk? Was the original sensor bad or was it the hoses that were cracked? We’re talking the same sensor right; the differential pressure sensor with two hoses?

OEM. We were on vacation 1,200 miles from home. The auto parts stores in town didn't have one, but the Ford dealership did. Both hose connectors had cracked off. The hoses were hanging down, unconnected, with the plastic tube piece still inside the ends. Yes, The DPFE with two downward hose connectors and an electrical connector.

 

[Brian Beckers]

I would. When your chasing a problem, you don't want to skip steps.

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I will check the EGR valve next then.

I feel very confident that my problem is some kind of vacuum leak, whether it's a popped/cracked/broken hose or other component failure. All symptoms seem to lead me in that direction.

 

[1955moose]

They usually are. The extreme heat, and just time, makes the hoses dry and brittle. Some of the sizes, and strange bends can be difficult to find new. You may have to get ingenious, even if temporary, I have many a times.

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[Brian Beckers]

Well, EGR valve seems fine. I put 15 inches of vacuum on it (engine off) and it held. Then while engine running, applied vacuum and the engine almost stalled. So, I'd say the diaphragm is working properly and I believe that would indicate there is not too much carbon build up.

Since it seems to run fine when cold, could there possibly be an issue with the IAC? How can I test it to rule it out?

 

[BRIANGEE]

I wouldn't think IAC w/ your symptoms. You really need some direction at this point and I think the only way you're going to get that is by reading the live data feed with a scan tool. I'd be particularly interested in seeing the 02 sensor activity and fuel trims. Also, just being able to see all the other sensor readings would be a great help - like MAF readings, IAT and ECT sensors.