Running Rich

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Sep 27, 2004 | 10:56 PM

miked79928

Thread Starter

Mountain Pass

Joined: May 2004

Posts: 201

Likes: 1

From: El Paso, TX

Running Rich

Need your guys help with this one. My 89 F150 with the EFI 4.9l seems to be running rich. It does not give off any codes, but it uses a whole lot of gas and the exhaust smells to high heaven. It just started to do this abot 3 months ago. Is there any way to lean out the air/fuel mixture? Any help is appreciated.

Sep 28, 2004 | 06:07 AM

EPNCSU2006

Lead Driver

Joined: Nov 2002

Posts: 9,557

Likes: 44

From: Concord, NC

Check the fuel pressure and the fuel pressure regulator to make sure the pressure isn't too high, and that the regulator is not leaking fuel to the vacuum port.

Sep 28, 2004 | 12:34 PM

miked79928

Thread Starter

Mountain Pass

Joined: May 2004

Posts: 201

Likes: 1

From: El Paso, TX

Thanks. I will check that out.

Sep 29, 2004 | 03:06 PM

miked79928

Thread Starter

Mountain Pass

Joined: May 2004

Posts: 201

Likes: 1

From: El Paso, TX

Ok. This morning I pulled the codes again and I got code 41, which means that the oxygen sensor was reading lean all of the time. I replaced it and I think that it was the problem. The exhaust smell is not as bad, but I will have to see what kind of mileage I get on this tank to be sure.