My Service Engine Soon light just came on, after doing a bit of looking on the site I saw that Autozone will scan codes for you....So I dropped by and they did indeed check my 'puter. Got codes 401 and 402. Restricted flow and Excessive Flow, so I went ahead an ordered an EGR valve.

Anybody see these codes and not have it be the EGR valve?

Big thanks to Autozone, I got to get me one of the OBDII readers pretty soon.

darth

 

my dealer replaced my EGR valve after that code problem,it was definitly the problm. thhis made a big difference in both power ,and fuel mileage. hope it does the same for you.

 

Does your truck have less than 50,000 miles on it? If so, the EGR should be covered under the emissions warranty.

I bought a cheapo (~$140) OBD tester a couple years ago, and I have used it many times. Well worth the money!

 

At what interval should the EGR valve be change out? I will be doing a tune-up this weekend (almost 90K), should I chane out the valve?

 

Changing the EGR valve is not a routine maitnence item. If you feel you need to do something, you can remove it and clean all the carbon deposits off the internals.

 

OK, I fixed it...well, I bought a OBD II reader...and a EGR valve. Cleared the codes without replacing the EGR to kind of see what the error rate is....now 5 days and no error. When/if it errors again I will clean it out to see if that is the issue. For now...I have a extra EGR valve, but that's ok for now.

darth

 

I just now installed the EGR Valve. I have been getting the 401 code about every other day. I clear it and then in a couple or more days it trips again.

Okay, now i got it baselined. I installed the new EGR valve and viola...I got another error 401.

So it isn't the EGR Valve, what else can cause the error 401? I did get one code 402, but just got it once.

thanks, darth

 

could be a vacuum leak

check your upper intake for cracks

 

The two lines that go to the pipe that connects to the egr valve they go to the sensor that will tell you if something is wrong. Check those vac lines and all piping connected..

 

I will definitely be checking the Vac lines and all connections. I also thought there was a DPE sensor (spelling?) that could go out as well.

I hate intermittent problems like this, especially when it only trips every 2 or 3 days. Heat seems to have no bearing on it, since we have had 95 degree days and as low as 55 deg days and have had failures at both temps.

thanks, dc

 

Those hoses go to that sensor

 

EGR is one of those things that you can replace when it fails or replace routinely. My experience is that they will start to get flakey around 60 to 80K miles. By flakey, I mean they will occasionally start to act up and then be fine. Sometimes just testing them with a vacuum pump seems to "cure" them for a long time. I am guessing that putting a vacuum on the diaphram pulls the valve more than normal and causes the valve to clean itself, like I said a guess.

Sometimes the rubber hoses deteriorate and that is all you need to replace. They get brittle and leak.

Some EGRs can be cleaned with a carb cleaner of solvent. i have even seen a few with little windos or doors that you open and spray in some carbon cleaner. If you still have the old one. Pull a vacuum on it to see if the diaphram is good, if it is you might clean the old EGR and have it as a spare. Some people feel replacing is just cheaper, but I like to tinker.

One thing to be careful about when changing the EGR is that some of them use "corrugated" hose kind of like a gooseneck lamp, and that metal hose gets real brittle and will break when you mess with the EGR, so you might need toreplace that too. Also some EGRs have a thin metal gasket. Don't loose it. Many EGR kits do not include the gasket.

Good Luck,

Jim Henderson

 

where is the egr valve??

 

do what I did, go buy one and then look in the engine compartment and you will learn.....

Back of the intake manifold near the firewall on the center/right. It has a rigid hose that comes up from the exhaust manifold, and a black vaccum line coming out of the top and going...well I don't yet know. ...i hear it goes to the DPE sensor.

dennis

 

thanks I,ve been geting a interminted check eng light this last week i'll do the auto zone check.
will this help bring the milage back up and some of the lost power.
how about the o2 sensors?

thanks
dave