Contour Enthusiasts Group Archives Forums General Troubleshooting Hesitation / bucking and code P0402

Hi all, I'm sorry if this has been aked before (I did a search) but here are my symptoms, I hope someone can help...

'98 contour V6 DOHC 110,000 miles

Getting a code P0402, already replaced the EGR valve last night. I don't know if it fixed the code yet but the problem below is still occuring.

The problem is that when driving (taking off from light) there is a lot of hesitation and a bucking sensation. This "bucking" happens while driving at a constant speed (any speed) and also while idling in park, (the "bucking" is a lot worse when accelerating though)

My question is, could this be related to the EGR system and if so what part is next to replace?

Any help is appreicated! Thanks!!

Most likely plugs or wires. Changed those recently? If so, I hope you used Motorcraft plugs & wires or Magnecore wires & Autolite double plat plugs. You've also gotta pay attention to the plug wire routing. They are not a direct match from coil to plug location. Almost, but not quite.

I tried to change plugs / wires once before using bosch platinum plugs but was unable to change the wires... it seemed too difficult. Car ran like crap after plug change (I did gap them correctly and torqued (sp) them correcly when installing. I ended up putting the old plugs back in and then everything was fine.

I'm almost thiking plugs too but am going by what the code says.

I am really wondering if the EGR system could cause the problems described? I want to stay away from the plugs until it gets warmer out.

Very unlikely the EGR system has anything to do with the symptoms. When things warm up a bit, do the plug & wire thing, it is easy. Use the brands I suggested or you run the risk of wasting your money. The Bosch experience should be your first clue to that. Also do THIS. TB cleaning. Also very easy to do with simple hand tools.

If you did have the wires disconnected for a time for the plug change, please double check your wire routing. Very common to mix two of them up & cause the symptoms you describe. If you have an original coil pack, the numbering should be on it.

don't forget the DPFE sensor under the egr - both work hand-in-hand

What symptoms will a bad EGR valve or solenoid produce besides a MIL or CEL?

Air leak symptoms. Stumbling at tip in, poor idle, etc.

I found out the hard way....DON'T change the EGR WITHOUT changing the DPFE...otherwise, you are wasting your time... I picked up both from Autozone for around 100$. It took about 30 minutes to swap themboth, just make sure you have a big honkin' box wrench to take the EGR off!!! I think it's like 1 1/2" inch or something...