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p0470 Code on 95 F350

35K views 18 replies 6 participants last post by  coyconner1983 
#1 ·
The truck has been running great until today... I went to work and went out to the truck and fired it up and it was running good, then all of a sudden it was having a real rough idle and the cel was on.. Sat there for about 4 or 5 mins and then all of a sudden the engine light went off and it started running great again.. Drove it about 15 miles shut it off, refired and idled good for about 5 secs then cel light and rough again.. 5 mins later cel is off and truck ran fine back to work.. (The check engine light goes off and right when it goes off the truck runs great. the second the cel comes on the truck runs like crap). Does this sound familar?

Error code p0470

Thanks
 
#2 ·
p0470 exhaust pressure sensor circuit malfunction, biased sensor, open signal return
 
#3 ·
Probably won't be all that helpful, but here's the pinpoint tests for that code (may provide some insight). They differ for the KOEO (H1 and H2) and continuous (starts at H3) versions of the codes.

H1 DIAGNOSTIC TROUBLE CODE (DTC) 0470

DTC 0470 indicates an EBP sensor malfunction was detected during KOEO On-Demand Self Test.

Possible causes:
-- Faulty EBP sensor
-- Open signal ground
-- Faulty PCM

NGS Tester installed. Key on/Engine off. Select EBP Pid from the PID/DATA monitor menu on NGS Tester. Is EBP reading below 18.5 psi?

Yes: CLEAR DTC and RERUN KOEO On-Demand Self Test. If code is still present, REPLACE PCM.

No: GO to «H2».

H2 SIGNAL GROUND CIRCUIT CHECK

Key off. Disconnect EBP sensor connector. Inspect for loose, damaged or pushed out pins. Repair as necessary.

Measure resistance from Pin A [Circuit 359 (GY/R)] to chassis ground.
Is resistance less than 5 ohms?

Yes: REPLACE EBP sensor. CLEAR DTCs and RETEST.

No: REPAIR open in signal return Circuit 359 (GY/R). CLEAR DTC and RETEST.

H3 CONTINUOUS DIAGNOSTIC TROUBLE CODE (DTC) 0470

Continuous DTC 0470 indicates an exhaust back pressure malfunction was detected during normal driving conditions.

Possible causes:
-- Faulty EBP sensor
-- Faulty connection
-- Faulty PCM

NGS Tester installed. Select EBP Pid from the PID/DATA monitor menu on the NGS Tester. Observe the PID while performing the following:

-- Grasp the vehicle harness close to the EBP sensor connector, wiggle, shake the vehicle harness while working towards the PCM.
Does the EBP reading fluctuate?

Yes: ISOLATE intermittent connection problem. CLEAR DTCs and RETEST.

No: GO to «H4».

H4 CONNECTOR INSPECTION

Disconnect EBP sensor connector. Inspect connector terminals and sensor terminals for signs of poor connection or corrosion. Inspect connections at the 42-way and PCM connectors.
Are all connections good?

Yes: Unable to verify problem at this time. CLEAR DTCs.

No: REPAIR connection concern as required.
Cheers!
 
#4 ·
I have more symptoms since i had time to mess with it today... Real rough idle,engine has a different tone to it,no boost while reving up, egts running around 4 to 500 degress at idle,when i turn the truck off it sound like a airplane.. I looked for the sensor to unplug it and i cannot for the life of me find it. Can someone please post a pick of it on a OBS.

Thanks guys
 
#6 ·
you will only make boost under load. it's normal not see any boost by just reving it up..
 
#8 ·
Yes, Pull the cover off (if your talking the black shroud). it will be in the same spot as on the website
 
#9 ·
PowerStrokeNation : Ford Powerstroke Diesel Forum

Well i think i found the sensor.. i unplugged it and started the truck and didnt help it at all.. Do i need to erase the codes then try it again? The truck is at work and i want to get it home so thats why i am trying the easy stuff first. Since its still doing it then im guessing the sensor is good and maybe the pipe is clogged?
 

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#10 ·
i came back up this morning to work and disconnected the sensor and cleared the codes and now it will start for about 2 seconds and shut back off. no throttle response what so ever. I was able to pull a second code and it was p0472. I data streamed the ebps and it stayed around 22.1. that was with the truck off and with it running for the few seconds it did. what does the 22.1 mean? is it good or bad?
 
#11 ·
po472 is from the ebp being unplugged or clogged, won't cause a no start.
that is the only codes your getting? what scanner are you using?
 
#13 ·
the only two codes i have got is the p0470 and p0472.. Im using the edge evolution that came with the truck. When i first got the truck i ran the codes and came back with nothing except the code for the programmer.. When the truck started this rough running a few days ago is when i got the p0470 and after i unplugged the sensor.. If i clear the codes as soon as i turn the key back on the po470 code is right back on.
 
#14 ·
Here's how I clean out the tube: Remove the tube. Get some suitable sized wire rope and chuck it in a variable speed drill. Use some carb cleaner with the wire rope/drill just like a plumbing snake to clear the soot. Make sure you also get the little section left at the sensor and the sensor too. Cheers!
 
#15 ·
well got everything cleaned up including where the sensor sits.. cleared the code and turned key and the p0470 returned.. the truck seemed to start easier but still rough idle. so ordered a new sensor from oreillys and it will be here in the morning.. It took about a hour and a half and finally got all the crap out using weedeater line.. Im hoping this fixes my issue
 
#18 ·
If the external connectors were bad enough to require replacement the valvecover gasket needs to be changed as well. You can check the undervalvecover harnesses when you replace the gasket. Anytime any of the connections have melted/burned (either external or internal), always replace the gasket or you will probably be replacing the connection again! Cheers!
 
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