P0402 help

[Chris H 3]

I have a CEL issue with my 2002 ST. The code reported by Advance is P0402. I replaced the EGR valve and disconnected the battery. This did not clear the light.



The symptoms are that engine RPMs drop when I put it into park or neutral. The engine is able to recover to a ‘normal’ idle is a second or so.



I was considering replacing the DPFE since it comes up often in discussions about this code. A Ranger owner suggested I replace the O2 sensors. It’s a slippery slope, I tell ya!



Any advice?

 

[Todd Z]

Replace the DPFE Also check the egr solenoid to make sure it is not sucking vacuum at idle...



Todd Z

 

[Allen Davis]

I just worked on a 2002 Ford Explorer with same problem and got a code of P0402 and at the beginning of the problem the engine was idling slightly rough or barely noticeable. Cleared the codes in the computer, engine was smoth again and ran it for 2 months until service engine light came back on again. Checked codes again whick pointed to DPFE EGR Sensor and also had other codes that said engine or cylinder misfire so if you did not replace spark plugs for a long time, replace them. In the 2002 Ford Explorer I replaced the DPFE Sensor and put in new spark plugs and engine runs like a champ again.

 

[Chris H 3]

So I bought a replacement DPFE sensor but it is bigger that the one that is installed. I suspect that this is a model year issue since I have an 02 built in 12/01 with the oil fill on the passenger side. That makes it a Job 2, right? I looked at the auto parts store and the 03 part is the same as the one I bought. What the deal?



Was the Job 1/Job 2 issue a half year model change? If I have job 2 why does it appear to not take 02 parts? Is the Auto parts store just mistaken?



Does this picture work?

 

[Chris H 3]

Heres a picture I hope

[Broken External Image]:



Man, that's painful.

 

[Jake Levin]

Chris, I have an '02 as well. I had to replace my DPFE sensor and the new one from ford was longer then the old one, but it fit and I've been fine for over a year now with it

 

[MJ L]

Ahhh...the good ol' P0402 code. I have the same thing on my '02 as well. Will be fixing it as soon as I get off my tail and purchase the part.