I had an issue last year with the F350 in my signature where the SES engine light would come on after starting when cold and would go off by the time I hit the end of the block...no other issues. So this year it's doing the same thing again except a few issues. First, it's not starting like it typically does when not at normal operating temperature...in other words, it takes longer to start and doesn't start with an explosion...if that makes sense. If I drive it to the hardware store it starts like it should when I get in for the drive back home and no SES light comes on. So now after the SES light goes off after I make the end of the block I notice the idle is higher when I come to a stop light...like maybe 850 rpms or so. Once the truck is all warmed up, this goes away. So I checked the codes today with the truck cold and I get P0470, P0603, and P1280. I realize the P0603 is from the chip. I did recently clean the exhaust back pressure sensor...EBP...and ran some hard wire down the tube.

After reading some threads I was thinking it might be the engine oil temperature sensor...EOT...but now not so sure. To me it is leaning more towards the EBP sensor.

 

If you remove the chip, what happens? Sometimes a chip can mask your problems until things get really bad. See if things get worse with no chip, or if your slow start becomes a smokey really hard to start.

Not enough info yet, but shooting from the hip, I'd take a first guess at worn injectors not firing when cold but working fine when warm.

 

I reset truck back to stock and cleared codes. Drove truck a couple miles and SES light stays on after start up and goes off at the end of the block like before. Roll over start seems the same but may be a tad better. I got back home and cleared the codes and did not crank. The P0470 code still shows up when I go and check the DTC's without starting and I would assume the other 2 would come back if I started. I have always left the tow safe tune in it but may try the high horsepower tune and see what happens.

 

Just to be sure, what are you using to pull the codes? I assume you're using something that can read the engine codes on these trucks since you're seeing the P1280, and that will set the light, I just want to make sure there's not more that you're missing.

If you unplug the EBP sensor, does anything change?

 

Okay so I tried some things with it today. With stock tunes I got the SES light staying on after WTS light so I decided to clear codes and see what happens. Cleared them and checked again without starting and they popped back up. Went ahead and started then shut off after just a few seconds. Checked and cleared them again. So I decided to install the Off Road tune. After install I cleared codes again and afterwards no SES light. I went ahead and started, drove a couple miles, then checked codes when home. The P1280 code went away but the other 2 were still there, so I cleared them and will see what happens tomorrow. It did show a P1000 DTC somewhere in the mix...

 

Using a Superchips 1705 tuner I have for the Excursion...I utilize a Superchips 1700 for my truck.

I have not tried disconnecting the EBP sensor and will try that tomorrow. Should that be done before cranking the motor?

If you read my prior post you will see the P1280 went away and so did the SES light.

 

Generally it is best to completely remove any tuner from the truck to diagnose problems, not just switch it to 'stock'. Though I don't know anything about the Superchips setup.

 

It's a tuner not a chip that connects and changes via the OBD-II port.

 

So I looked at the ICP sensor and there is a little oil in there. However, it is my understanding that when the ICP sensor is bad it runs rough, which mine is not, and why I did not disconnect while running to see what happens. I started to clean and check, but I also read the oil would help the electrical connection.

I don't have a problem pulling the ICP sensor out of the Excursion and put in the F350, but am worried if the o-ring would leak when it goes back in the Excursion.

 

Okay, so what I have noticed with the off road tune in is it starts like it's supposed to. However, I get a 200rpm-250rpm higher idle...like 850rpm...for about a dozen miles. I recall another person here that had the same issue and it turned out to be the EOS or engine oil temperature sensor.

 

The codes alone while running non-stock tunes in there aren't getting you anywhere. I would return it to a bone-stock tune, then I would use an OBDII app like FORScan to really troubleshoot the issue(s). Useful inks are in my signature.

 

Tugly, thanks for the input. I ordered and now have an OBDII with the switch and can download the Forscan. It seems a little complicated but hopefully nothing messes up on the learning curve...