Mr Paul [T-28]

So the work I did on Saturday cleaning my EGR passage way (see two posts down) was for nothing.

This is the third time that I have done this procedure, and now my check engine light is on again. I will pull the codes tonight, but I am 99% sure it will be 16785 (or whatever) EGR insufficient flow.

This time around I made sure that I had the passage way completely clean, but the CEL came on anyway.

This leads me to believe that the EGR valve itself is bad. Is there a way that I can check this myself without spending $250 for another just to see if it works?

BTW, all the vaccuum lines are OK too.

Suggestions?

Thanks

GPJ

Try a couple of things:

1. Disconnect the vacuum hose to the EGR and plug it. Connect a hose to the EGR, and while the car is idling, suck on the hose. The engine should stumble, if the valve and passages are ok.

2. If ok, the EGR temperature sensor may be bad (or the vacuum system plumbing).

Mr Paul [T-28]

thanks for your help. I will try this tonight.

BTW I snapped a pic of the vaccuum leak that I had, but for whatever reason Audiworld couldn't upload the picture into my picture poster.

GPJ

...let me know how it works out. Is the pic too large?

Mr Paul [T-28]

The pic shouldn't be too large. Other photos that I have uploaded were the exact same size. They are both JPEG's just like all other pictures I have uploaded. I don't know what the problem is. I will try taking them with another camera and try again.

Mr Paul [T-28]

I had 4 fault codes, none of which has to do with EGR, but probably the work that I did.

16554 - Fuel Trim, Bank 1 Malfunction
16555 - Fuel Trim, Bank 1 System too Lean
16557 - Fuel Trim, Bank 2 Malfunction
16558 - Fuel Trim, Bank 2 System too Lean

I went ahead and tested the EGR valve too, like you described, and the idle really stumbled - almost died. So I guess the valve is functioning and the passageway is clear.

Let me know what you think about the fault codes.

Thanks for the reply and retort G Peen Jr.

t0adman2.8

Oh man, this sounds terribly famililar. I just had my EGR system cleaned out at the shop while they were doing some other work and I threw a CEL the other day. I'm guessing it's going to be the same Insufficient Flow message. Please keep us posted on how the testing goes and any more insight you gain troubleshooting it.

By the way, do we run the risk of doing damage to the engine by leaving it flowing insufficiently or is it just a ecologically unfriendly thing to do?

GPJ

Re: lean fuel trim...

According to Bentley, since both banks are lean, you probably have one or more the following:

1) a large air leak quantity in intake system to Mass Air Flow (MAF) sensor.

2) leaks in the area of the fuel lines.

3) vacuum line to fuel pressure regulator or fuel pressure regulator faulty.

4) fuel filter plugged.

5) fuel pump delivery quantity too low.

6) EVAP canister purge regulator valve sticks mechanically in closed position.

I'd reset them (disconnect battery for awhile) and see what pops up again.

Mr Paul [T-28]

Thanks for all of the scenarios. I just bought a fuel filter, so I will try that first and see what happens.

I cleared all the codes tonight with my VAG-COM, so we will see if they come back.

I will keep you updated.

Thanks again.

Mr Paul [T-28]

I ran for 8+ months with EGR problems, so you are probably OK.