EGR valve and gas mileage

[haro1225]

Since I've had this car, occasionally while crusing at a steady pace I would get a CEL and the code was always P1406....which is for a failed EGR valve. I never really paid it much attention since it wasn't happening but maybe once a month. But lately its been doing this everyday now. And it seems like my gas mileage is suffering. Could the EGR valve be causing this?

[ChilinMichael]

Sure could.

[repinS]

My bad EGR on the 95 sure did. Lost 2-3 mpg, especially around the city.

[00Beast]

Yes, replace it. Get a new Delphi from either Amazon or Rock Auto. The auto parts stores charge an arm and a leg for them...

[Wes]

Sorry to disagree Ed, but I would suggest he try to clean it first. It is common for those to fail simply because of carbon build up. Spend 10 bucks or so on some cleaner and a gasket before you spend over 100 on a new one. I do agree on Ed's replacement suggestion though if its needed.

[00Beast]

There isn't much to clean on these modern ones. They either work or they don't, unfortunately...

[ChilinMichael]

Ed's right, not like the old ones...there's not much to clean. You can clean what you see, but it has little effect on the mechanism/unit itself. A standard motor products for your car is $65, next one is original engine management for $92.

[00Beast]

http://www.amazon.com/Delphi-EG10169-EG ... &carId=003

[clm2112]

And it seems like my gas mileage is suffering. Could the EGR valve be causing this?

Yes. EGR allows the engine to run leaner mixtures while suppressing detonation. Once the PCM notices the valve isn't working, then it reverts to a richer mixture/less ignition advance and flags the error. So you loose the lean cruise on the engine and your fuel consumption goes up.

On an older car, like my '94 Camaro V6 (OBD-I), the symptoms are reversed...a failed EGR on that car resulted in better fuel consumption, since the PCM software didn't adjust for failure of the EGR valve, it just flagged it was stuck everytime the car decelerated from a steady cruise (coming down an interstate exit ramp.)

Check your wiring first (clean contacts on the connector and look for charred wires) and if the code keeps returning then try cleaning or replacing the actual valve assembly like the others suggested. There's no harm is trying to clean the EGR valve first (just the cost of the gasket) and see that the passages leading to and from the valve are not plugged with carbon.

[Wes]

Sorry, but I respectfully disagree. I have seen many people with egr codes clear them with just cleaning. I get what you mean about the older digital ones like on my 93 L67. But, I have seen many linear GM egrs work for months and years after just cleaning the soot free from that little pintle valve and getting it to move freely will allow it to function again. I know that will not always be the case and if it is the electronics that failed, then of course no amount of cleaning will correct that. Just my 2 pennies, I prefer to clean them before replacing.

[repinS]

Digital EGR can often be cleaned with positive results. Ryan's 96 SSEi has Linear EGR, which doesn't respond to cleaning nearly as well, if at all.

[clm2112]

Digital EGR can often be cleaned with positive results. Ryan's 96 SSEi has Linear EGR, which doesn't respond to cleaning nearly as well, if at all.

I think the point being made is that even if cleaning is unsuccessful, there's no harm in trying that before buying a new valve. Gasket is cheap.

Same rational for why I always start my diagnostic advice by suggesting a good inspection of the wires & contacts involved in the fault. We know they corrode over time and are in a harsh enviroment. And checking them over costs nothing.

[repinS]

Not disputing that - just merely suggesting the success rate of cleaning the linear EGR valves. I did the same when mine went.

[impala67]

just stupid question, where is this egr valve located exactly? at exhaust manifold i suppose?
i wanna try cleaning mine too- although i dont have trouble codes, just to see how it looks like... new ones are atleast to 91 buick over 60-110$ so trying to clean it isnt necessarily bad idea.

[clm2112]

just stupid question, where is this egr valve located exactly? at exhaust manifold i suppose?

The valve is near the valve cover. Find the corrugated steel tube from the intake manifold (near the throttle body) and follow it to a black plastic can with a connector on top. Under the plastic top (which is electric actuator) is a cast iron body. That's the EGR valve itself. Bottom side of the valve goes to the exhaust manifold.

In this photo, look at the radiator hose and front torque mount. You can see the EGR valve tucked in between them.

[primetime2]

try this link instead save a couple bucks and get the same one as above mentioned

http://www.ebay.com/itm/NEW-DELPHI-EGR- ... 900wt_1270

[00Beast]

That's a good deal.

One word of warning: The gasket that comes with the EGR valve may not fit. I had bought a fel-pro and it fit just fine, but the one that came with the Delphi EGR wouldn't fit over the studs, for whatever reason.

[haro1225]

Thanks for the advice guys. I went and got a used EGR from the junkyard for $8 and I bought a new gasket. I pulled mine off and I found that the little piston was totally seized closed. On the used one the piston moves easily if I push it with my finger, and there is much less carbon in it. I cleaned it up and put it on there with a new gasket just now and I'm gonna see if the code comes back. If it does then I'll get a brand new one.

[haro1225]

I finally got a chance to fill up after I changed out the egr. Before I swapped it the last fill up was 16mpg, this past one with the new one was 22mpg. I can live with an improvement like that

[clm2112]

I can live with an improvement like that

I'll bet you could

Now if I could just get the 302 Ford to get better than 14mpg