Jumps in and out of overdrive and third @ around 43mph on long gradual incline

[The lawn shark (tls)]

Checked the codes and it throws a p0238 boost sonsor (a) high cir and a po470 exhuast press sensor cir...
Any ideas......oh rebuilt tranny 3,000 miles ago.

[The lawn shark (tls)]

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[elibenson]

The back pressure sensor is no big deal. Nearly every 7.3l truck has a problem with it's back pressure sensor being coked up by now. Not everyone scans their truck for codes every day, so most of them are having this problem. They are at least 6 years old now. Unscrew the sensor and clean the tube out with a piece of flexible wire. squirt some brake clean or carb cleaner down the tube till it's opened up. I prefer brake clean. clean the bottom of the sensor and put some anti seize on it before you put it back in.

It is really no big deal that the EBP sensor is not working, it shouldn't affect driveability. I think it will only cause a problem on really cold mornings.

The boost sensor high circuit code is probably caused by a bad sensor. This one might affect performance. If the computer doesn't know what the boost is, then it may not be injecting the right amount of fuel. I would suggest replacing the sensor.

[The lawn shark (tls)]

Originally Posted by elibenson

The back pressure sensor is no big deal. Nearly every 7.3l truck has a problem with it's back pressure sensor being coked up by now. Not everyone scans their truck for codes every day, so most of them are having this problem. They are at least 6 years old now. Unscrew the sensor and clean the tube out with a piece of flexible wire. squirt some brake clean or carb cleaner down the tube till it's opened up. I prefer brake clean. clean the bottom of the sensor and put some anti seize on it before you put it back in.

It is really no big deal that the EBP sensor is not working, it shouldn't affect driveability. I think it will only cause a problem on really cold mornings.

The boost sensor high circuit code is probably caused by a bad sensor. This one might affect performance. If the computer doesn't know what the boost is, then it may not be injecting the right amount of fuel. I would suggest replacing the sensor.

What sensor would I replace to fix the boost sensor high circuit code

[elibenson]

It's located on the passenger's side of the engine compartment attached near the firewall. Actually, it's screwed to the housing for the A/C evaporator. It has a 3 or 4 wire plug on it, and it has a 1/4" rubber hose going into it. The hose runs back to the center of the engine and connects to the intake runner. The hose carries the air pressure to the sensor. I've never bought one. I don't know if you can get one from the regular parts stores (Auto Zone, Oriellys, etc). You may have to go to the Ford dealer..