P0404

tbclrk · July 9, 2009

so i was driving home and all of the sudden this code popped up. the scanner said exhaust gas recirculation (i know thats spelled wrong) circuit range/ performance.

what does this mean? i have dual exhaust, would this be the issue.

actually the light just went off today, is there any issue i should worry about?

bill190 · July 10, 2009

There is an exhaust gas recirculation VALVE....

The engine computer tells this valve to open a little, more, or a lot.

Then the engine checks up on this valve to be sure it did what it was told. Did it open a little as told? Or more when told to do so? Or a lot when told to do so?

Sounds like your exhaust gas recirculation valve is being naughty and not doing what it was told!

tbclrk · July 10, 2009

There is an exhaust gas recirculation VALVE....

The engine computer tells this valve to open a little, more, or a lot.

Then the engine checks up on this valve to be sure it did what it was told. Did it open a little as told? Or more when told to do so? Or a lot when told to do so?

Sounds like your exhaust gas recirculation valve is being naughty and not doing what it was told!

thank you very much for your response

so is it something to be worried about? will it cause problems in the future?

if it is an issue is it something i can fix myself?

bill190 · July 10, 2009

What that valve does is send exhaust into the air intake of the vehicle and this reduces emissions.

The thing is there are times when this can be done and other times it is best for the engine to get mostly fresh air. And the engine computer determines when this can be done/not done.

If the valve is not working right (because it is dirty and stuck), you could get a situation where exhaust is being directed into the engine when it shouldn't and then the engine runs poorly and in severe cases it might not run at all.

If it were me, I would replace it right away because I like everything to be in good working order. And this gives me a more dependable vehicle.

As to if you can replace this or not, I don't know. Some people are "mechanical" or "handy" and others are not.

Everybody is good at doing something. Some are good doing this, others good at doing that.

Now I'm good at electrical/mechanical things, but I can't learn to play a piano or learn a foreign language to save my life! I just can't do it!

So make up your own mind with that. If you want to try, you would need to right tools and good instructions. For something like this, a Haynes or Chiltons repair manual might be the easiest to understand and be easier to find the section for replacing this part.

You can also order a factory service manual set from your dealer, but these can be a bit intimidating if you have not done much of this type of thing before. My 1999 set of books is 4 books, each book is 2 inches thick and around 3000 pages total. However if you can find the instructions for this, these would be the best and most detailed instructions for replacing the part. But sometimes like looking for a needle in a haystack.

And you can go to the auto parts store and get the part, then you would know what it looks like. Take your vehicle with you. They would want to know what year, model, engine, and maybe transmission.

Then after the part is replaced, the diagnostic code should be "cleared" with a code scanner.