My 7.3 Diesel

[Bduck]

One day last week I decided to take my dog on a road trip to get out of the house. As I came to the Morgan exit, I noticed a battery light flickering on the dash. That ended road trip and immediately returned home. By the time I got home the batt flickering started to settle into full time on. Checking with my multimeter found alternator quit charging. I've replaced the alternator before with a lifetime replacement from Napa. This makes about the 3rd time since purchased in 2006, good investment. Next, I put the DTC code reader on finding I had 3 codes. The first one was a "water in fuel" code which I had a spare filter draining & replacing filter. Also, found my "water in fuel" light wasn't working-possible bad bulb and need to go into dash researching, its suppose too briefly illuminate whenever ignition is turned on, out of site out mind. Next codes were exhaust back pressure sensor and exhaust back pressure high output sensor. The exhaust back press sensor is located at the front of the engine and the high output is in the exhaust pipe below the turbo. After gathering information, the exhaust back press sensor could be clogged causing other sensor to trip a code. Also, this sensor causes other issues such as excessive black smoke, fuel mileage dropped off from 18mpg to 12mpg, and hard shifting with the transmission. These symptoms I have with my motor but never realized something was going on as the truck ran well, if it hadn't been for alternator going down in my opinion. Not once did I get a check engine light. After changing sensor & line, both DTC codes cleared. I'm awaiting opportunity to do a good mileage check; excessive black smoke is now cleared up some but always had a little in the past when it was running right. Not sure yet with transmission shifting issue either at this time.




This is the exhaust back press line that

attaches to sensor at front of engine to front

of exhaust manifold passenger side







Sometimes the sensor line can be reused providing

it can be unclogged, this line is fully clogged. Also, I 

found 3 cracks in this short line making it unsalvageable. 

Unfortunately, this was a $90 purchase (OUCH) from dealer

which had it on hand. I could have gotten it for half the 

price and other sources would have to backorder which 

I couldn't get a date for delivery. 









This is the sensor, which is a $135 item, it was 
fully clogged, I tried clearing some of the 
harden black soot buildup. I opted also to 
purchase this from dealer since its manufactured 
by Motorcraft and in stock. I saw other wannabe 
sensors for a lot cheaper made in China, no thanks.