2002 Tauras P0402 DOHC

[scpalazzo]

The car has been running fine but it won't pass inspection because of the engine light. I changed the EGR valve and EGR sensor and disconnected the battery after each replacement but the light returned after a couple of days. What do I need to do?
HELP?


Steve

[Gunshot]

Run by Advance Auto and have them run and then clear the codes.

[UsedtobeSmart]

Originally Posted by scpalazzo

I changed the EGR valve and EGR sensor and disconnected the battery after each replacement but the light returned after a couple of days.
Steve

In recent model cars pulling the battery cable really won't do squat anymore -- they put a battery in the computer to maintain codes. Go by a big chain parts store, ask them if they can pull the codes, price out whatever it is they tell you that you'll need (and believe me, most likely they will tell you that you need to replace whatever part the code comes up as saying is troublesome), then ask them to clear the code and tell them you'll be back when the light comes on. Then, once it's clear, go get the inspection done.

Clearing the codes should keep the light from coming back for a while. But get whatever the problem is fixed ASAP too. Could be bad wires or a bad fuse or something -- did you check those? I'm not too familar with the Duratec, so maybe shorod will be able to help with the specifics.

[TaurusKing]

Resetting the light off will most likely guarantee an emissions inspection failure, due to the fact that the monitors are also reset to un-run mode and the car will fail..that code could indicate something as simple as a pinched or bad vacuum hose or lead to various failed related parts such as egr vacuum regulator, egr valve, pressure sensor, etc

[shorod]

Right, disconnecting the battery won't buy you anything and clearing the codes will clear the readiness tests. Some facilities will fail you for that and some will charge you extra to complete the readiness tests, then fail you when the P0402 reappears.

According to the factory service manual, possible causes for a P0402 are:

• EGR valve stuck open
• Plugged EGR vacuum regulator solenoid vent
• Plugged EGR tube
• Slow responding D.P.F. EGR sensor
• Damaged DPF EGR sensor
• Improper vacuum hose connection
• Plugged vacuum hoses
• EGRVR circuit shorted to ground
• Damaged EGR vacuum regulator solenoid
• Damaged PCM

-Rod

[UsedtobeSmart]

Originally Posted by shorod

...clearing the codes will clear the readiness tests. Some facilities will fail you for that and some will charge you extra to complete the readiness tests, then fail you when the P0402 reappears.

Did not know that. Thanks, rod!

[scpalazzo]

Thank for all the info but still have the problem. I think it might be a vacum problem, how do I find that?
?

[TaurusKing]

Sometimes the little piece of vacuum hose attached to the dpfe sensor rots out from the heat of the egr pipe, I'm not 100% if your 02 is like any of my older ones, but i've replaced them hose on all... what I would do is first inspect all vacuum lines for connections, splits, whatever.. 2nd check the egr lines for any signs of carbon builup, 3rd is I would buy an evr solenoid, I think it's probably less then 30 bucks.. they do go bad.. I'm not big on blindly replacing parts, but you've already replaced 2 pieces to no avail.. I've never replaced an egr valve nor have ever had carbon buildup issues within the egr system, at least not enough to cause malfunction and associated check-engine light.. I have had issues with dirty intake valves causing pinging, at least that's the resolution I finally came to after all others were worked through..A couple of cans of Seafoam fixed it, till the next time..

[tripletdaddy]

$30 ? Where do you get your parts so cheap, Rod? Its $50 my way.

[shorod]

You'll have to ask TaurusKing, he posted the $30 price. I suspect he did like I would have though and just threw out a guess.

-Rod

[TaurusKing]

I found it at Autozone, part evs58.. house brand Duralast, also have Wells, same price, probably one and the same..

[tripletdaddy]

Oops, my bad. I had the wrong group of years and wrong poster. Yup it is what you say it is.

[mwt47]

If you clear the codes it has to run so many cycles or your will get a code P0100 which means it has not completed enough cycles.

THe P0402 can be a dirty EGR valve. You can clean it out and use carb cleaner to finish cleaning it. That may or maynot be your problem. You can reuse the gasket. Just coat it in some anti seize.

The P0401 is usually the DPFE sensor.

Check for vaccum leaks.

Mike

[scpalazzo]

All the vacume hoses look good, thought that might be it. The car only has 72,000, I guess I'll buy a EGR solinod.
Steve