I just bought 6 days ago a beautiful 2008 Fit Sport in red, 137K and clean as a whistle inside and out, which is remarkable for an Ohio car. Looks like it was garaged for winters and got a lot of highway miles. NO RUST! Amazing... Ran smooth, peppy, just awesome. It's for my daughter and she loves it. It has a name already - Miss Fit.

I thought I got a good deal until last night. Warm and very rainy, and it started running rough at idle, then stalled and didn't much want to start again. CEL came on. I limped home OK in the rain and let it sit until morning. Googled a bit and decided it looked like a coil pack issue.

Started it up this morning, still running rough, CEL still on. Went to the auto parts store, had them read it, and it's throwing two codes - P0401 and P0404. Both relate to EGR (not cylinder misfires), so I looked here and elsewhere online and it seemed like cleaning it was the ticket.

Pulled the EGR, sprayed the crap out with carb cleaner and wiped it with q tips. Looks much better. Vacuumed the ports into the engine and got a lot off of it.

Put it back together, and ... same thing. Whole engine is shaking, runs rough, doesn't want to start, stalls.

Any ideas? Is there way to test that the EGR is actually working? Am I barking up the wrong tree?

 

Good news.

So my son's friend had come over, who is the car genius of the neighborhood. He's the one that actually did the cleaning work, to give credit where credit is due.

Now, he put a hex wrench in the piston of the EGR valve, and when he rotated it, it snapped back against the seat.

It had been stuck open!

Tried running the car with the EGR out, cardboard over the ports - ran fine
Put the EGR back in - car ran fine

Took it on the freeway for a short test, running fine now.

Tried running the car with EGR out and cardboard on the ports to see if we could see the piston move - car ran but EGR didn't do anything.

We're not sure if that means anything. When should the EGR open? Can we test the valve any other way?

 

The EGR is controlled by the ECM and there is no manual way to test it. If you block the holes and leave the EGR off you will throw a code eventually. Ask me how I know.

 

Very similar to my experience. Just over 60,000 CEL comes on, car bucks at approx. 2500 rpms, throttle response poor, dies at idle and hard to start. Scanner shows P0404. The service manual suggested cleaning the EGR valve. Sure enough, carbon particles were keeping from closing. Five minutes to disassemble, clean and reassemble. Car runs sweet and CEL is staying off.

 

Good job on the DIY fix. It's funny the UK version of the Fit has been having many problems with the EGR valve since they came out in the GD version and continue into the GE.

But the more emission controlled USDM have had few if any problem with the EGR.

 

That has been a common problem on many vehicles. The fix is always to remove the EGR, clean it (and the port), and exercise it to make sure it moves freely.

Years ago my daughter had a problem with her GM engine running very rough. She took thee car to my hangar to work on it inside and called her boy friend. By the time he arrived she had diagnosed the problem removed the EGR, cleaned it, and reinstalled it. It normally is not a big job. I did one on a Ranger one time that was a real bitch.

GM on some engines ended up putting a screen in line with the exhaust path to filter out the carbon from the valve itself. I have only once had to replace the valve. Every other one I got by cleaning them. I have no experience with EGR problems on the Honda Fit.

You should be good to go until it carbons up again.

 

^^^ IMO that's another reason to run the engine to redline occasionally...

The increased flow to both the injectors and EGR serves to keep everything running smoothly.

 

I recently got a used 07 fit off cl. Had a few issues but recenly started to stall and idle rough. Took it to the dealer to diagnose and they said p404 bad egr. They wanted 480 to put a new one in. Luckily i saw this before replacing it and got a can of carb cleaner instead. Sure enough it was stuck open and after 1 spray it snapped closed and that was it. Thank you all for sharing this info. Saved me 500 bucks. Think Im gonna vacuum out the chanels also when i get home