Just another newb question,

I was wondering what would set off P0472, P0478, P0470? I cleared the codes using my old edge evolution (handheld one) was not running a tune at the time and the codes have not come back. Could it be the EBPV tube getting clogged up or would there be any other major problem that will bite me in the rear end? I did some searches but none turned up all three codes registering at one time.

Thanks,

 

If they don't come back I wouldn't worry about them but it wouldn't hurt if you did this maintenance procedure. and checked the items in bold for P0478. These could cause the P0472 and P0470.

Welcome to guzzle's Exhaust Backpressure Sensor Cleaning Maintenance Web Page

P0478 - EPR Exhaust pressure control valve high input - Plugged sensor line, stuck butterfly, restricted exhaust

P0472 - EBP Exhaust back pressure sensor circuit low input - Open/grounded circuit, biased sensor, PCM

P0470 - EBP Exhaust back pressure sensor circuit malfunction - Biased sensor, open signal return

 

The same codes came up again this morning after a hard start. Had to cycle the key a few times untill the truck started. While cranking there was a lot of white smoke and then finally started and ran fine after that. After all these posts about hard starting and now is happening to me

 

All that cranking to start sounds like your GPR is not working. That white smoke is raw diesel fuel that is not igniting due to cold combustion chambers. Glow plugs not getting hot.

Since the P04xx codes returned the first thing you should do is the EBP Sensor and Tube cleaning. That link I posted will guide you.

 

Thanks,
I guess I know what I'll be doing this weekend...better get some beer.

 

This should help with testing your GPR. If you see 2 relays similar to this the GPR is closest to the firewall. The other is the AIH (air intake heater) relay. Early 99s do not have an AIH and I don't know what year your truck is.

 

Thanks for the info, the truck is an 03 7.3L with 125K miles. Never had a problem before.

 

Then you have an AIH relay and the GPR is right behind it.

This is what my GPR looked like at 82k. It still operated but the contacts were so pitted it did not pass power to the GPs.

 

Great pics...truck seems to lack the power it used to have and still need to get to working on it, maybe this weekend since I can't seem to get the time to work on it.

Thanks again

 

I just replaced the puny stock GPR with a Stancor relay today. CLICK HERE