exhaust backpressure code affecting tranny shifts
 

so heres the deal ive been catchin this back pressure code ever since i put the programmer in my pickup. i didnt think the code was affecting anything, but at the same time i put the programmer in my tranny began to shift differently. when accelerating away from a stop sign when i reach 45, or when it shifts into 3rd gear it feels as though the torque converter is being locked up and then imediatly it hits 4th gear the same way with the torque converter locked. so when it shifts to 4th gear its only running about 1000 rpms. really makes pullin a trailer hard. so today i was messin around w/ my tunner as i pulled up to a stop sign. it threw that same code and as i was accelerating away it did the rpm drop but just as it did that i cleared the code and the torque converter unlocked and i gained the rpms back. i pulled it over and accelerated up to speed again, and it shifted beautifully. i had always assumed the different shifting was part of the programmer, but now i dont know. sorry i dont have the code number i never wrote it down, and i cant get it to come up again. help please....

Probably got the P0478 code. This happens when the tube leading to the sensor get clogged with soot. When you set this code, it causes the PCM to set a defuel mode. Probably why you are getting such strange tranny shift patterns at the same time.

Clean the tube and sensor. The tube comes out of the passenger's side manifold and leads to the front of the engine where the EBP sensor sits. Unbolt the sensor and use a long wire brush to clean out the soot.

thanks ill give that a try

any word on the fix? did it work? I get the PO470 code (back pressure sensor) I have simliar symtoms

where is this sensor? and best way to clean it?
thanks

https://www.ford-trucks.com/user_gal...id=124588&.jpg
Remove the sensor (be careful not to apply lateral force it can break the sensor) and spray with Braklean then take some 0.95 square weedeater line or similar and scrape the inner sides on the bottom of the sensor (Dont go to deep it can damage the sensor diapram inside). The remove the tube below the sensor mount (A crowfoot wrench comes in handy here) the other end is on the pass side exhaust manifold. Spray with braklean and let soak for a bit. then take about 2.5 feet of the weedeater line and run it down the tube and work it back and forth do this 3 or 4 times and it usually clean it up.

that fixed it guys. thanks... i sure appriciate the help u all offer on here. great show. thanks again

I will look into that, have to wait till it gets above Zero so I dont freeze my arse off.

P0470 code is a bit different. You might be able to clean it and fix the problem. But more than likely the sensor itself is bad and needs to be replaced.

Looks like I might hafta give this a try. Can this sensor and tube be purchased anywhere or are they dealer-only items?

I have the P0470 code showing up on my reader. I have the Diablosport Predator with the 110 hp performance tune installed. I found this thread utilizing the search engine but I am wondering what the best way to remove the sensor is. Is it best to use a large socket? Also, do you have to remove the sensor prior to removing the fitting for the tube under the sensor? I could not get the fitting loose under the sensor. I was able to loosen the fitting for the tube on the exhaust manifold. Anyways, any help would be appreciated.