EGR code P1403, weird whistle, exhaust leak

haydukelives33

New member
Joined
Nov 10, 2019
Location
Ithaca, NY
TDI
1999 Golf TDI
Hi all, I registered just recently because I wanted to ask a specific question to which I couldn't find an answer in past posts. (If I missed something, please feel free to direct me to it.) So here it is:
My 1999.5 Golf TDI hasn't been able to pass inspection in over a year due to the check engine light, but the car runs great. I have one of those knock-off VAG-COMs and the code it's showing is P1403: EGR regulation deviation.
I've replaced the N18 and N75 valves and all the vacuum hoses in that part of the system. That didn't help. I've also replaced the MAF sensor, which helped for long enough to pass inspection last time. CEL came back on after about 50 miles.
On the recommendation of KermaTDI, I had the intake manifold and EGR valve cleaned. The mechanic said everything was severely coked up. The car had been running fine, and still runs fine -- and that's great, but I'm out almost a grand and my car still won't pass inspection.
The car makes a high-pitched squealing/whistling noise at higher RPMs under load. Doesn't make the sound just revving in neutral.
There are two holes in the exhaust. One is just downstream of the flex pipe and the other is a foot or so downstream from that. I did my best to patch the first one with a Miller Lite can and a bunch of pipe wrap **** from AutoZone. I patched the second one with the same pipe wrap stuff. I wire-brushed all the rust off and followed the instructions. It still sounds like it has an exhaust leak, though, and after resetting the codes I got another 1403.
One more thing that may or may not be related: I have a slow coolant leak, but another mechanic pressurized the system and said it held. I have a feeling the leak is in the cabin heating system, though, because I can smell coolant whenever I turn on the heat.
So what I want to know is whether the two exhaust leaks I mentioned are enough to throw the 1403 code. And if not, what else could be doing it if the N18 is good, the car runs well, and the intake and EGR are clean? I've double-checked all the vacuum hose routing, and it's correct according to a diagram I found here in the forums.
My wife wants to sell it, and I want to fix it. I can't afford to have a mechanic throw money at it. Another question I have is how much is it worth? Intractable EGR code, runs like a top, 2-door, alloy rims, manual transmission, 180k miles, old tires, slight rust on the front fenders, decent-for-20-years white paint, fair interior, old tires, roof rack, trailer hitch, newly cleaned manifold, timing belt and clutch at 160k, and good glass?
Any help would SO much appreciated. And if anybody knows a VW guru near Ithaca, NY, that would be great too. I like the shop I take it to, but they don't pretend to be VW or diesel specialists.
Ok, thanks in advance! Take care everybody.
 

flee

Veteran Member
Joined
Sep 19, 2011
Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
Depending on how the EGR was cleaned, that could cause it to fail. They get old, too.
The EGR cooler below the EGR valve could be clogged and not allowing enough flow.
Try to locate a guru near you to avoid throwing more money at it.
Fixing the exhaust system properly should be fairly cheap but won't affect the CEL.
 

wonneber

Top Post Dawg
Joined
Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagen, 2014 Tiguan,2003 Jetta 261K Sold but not forgotten
Check if you have power to the N18 solenoid, possibly a yellow/black wire and a pulsing signal on the other wire, possibly red/blue.

Check the N18 for continuity also.

Cleaning just the EGR valve helped it but if the rest of the EGR system is clogged it still will cause the code.
Did you have the cleaning job done at the repair shop or did you take the EGR off yourself and take it to him?
 

haydukelives33

New member
Joined
Nov 10, 2019
Location
Ithaca, NY
TDI
1999 Golf TDI
Hey flee and wonneber, thanks for getting back to me. I got started last fall, got stuck on a rusted nut, and when it got cold I took it in to have them finish the job. They cleaned the EGR valve, the EGR cooler, and the intake manifold.

I think my multimeter is fried. A long time ago I replaced the fuse with a screwdriver bit and it's been acting up lately. I found a page from a service manual that says the resistance across the terminals on the N18 should be 14-20 ohms. That sound right to you?

I'll get a new multimeter and take those N18 readings again and report back. I was only getting about 9.5 volts across the battery terminals, and I read that the MAF needs to be getting at least 11.5 volts to work properly, so if my meter is right, I guess that means it could be a charging problem?

Any thoughts much appreciated! Thanks for all your help and advice so far.
 

flee

Veteran Member
Joined
Sep 19, 2011
Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
If the car battery is that low and/or not charging, fix that problem first, obviously.
As with any MKIV nowadays, make sure the vacuum system is not leaking.
A MityVac makes this a simple procedure. Check for leaks at each component/hose.
I have bench tested the N75/N18 solenoids with a 12 vdc source and low pressure air.
Also make sure the vent from the solenoids is connected to the airbox. This often
is ignored by someone working on the engine and can let debris get sucked into the
solenoid valves. A failing turbo actuator can also contaminate the N75 with rust.
If dirty, they can sometimes be cleared with a shot of air.
 
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haydukelives33

New member
Joined
Nov 10, 2019
Location
Ithaca, NY
TDI
1999 Golf TDI
Thanks tdijarhead -- I did see that, but I don't know enough about the vag-com to perform the output tests. I'll look into that. The valves both came from KermaTDI. Which pipe is the boost pipe? One of the accordion-looking ones that go to and from the EGR cooler? Or to/from the intercooler?

Flee, that's a good idea -- I'll pull the valves and bench-test them at work, then get a MityVac and go through the whole vacuum system. I replaced the hoses going to and from the N18 and N75, including the turbo actuator hose, but the fittings look a little suspect. The vent hose to the airbox is connected, but I think I remember finding it dangling in there at some point... could've sucked something in, I guess. And I can't remember whether or not I replaced that one.

Ok, this is good. I've got some direction now -- thank you guys! I'll post again once I test the battery and the vacuum system.
 

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
All the pipes, follow the plastic pipes from the egr down behind the headlight into the passenger wheel well and back to the turbo. Also the other pipe that connects to the turbo and comes up the back of the engine to the accordion and into the air box. Any of those pipes can come slightly askew, crack or just plain come off.

Since you have been into the egr system make sure all the metal egr pipes are tightened down. I forgot to tighten one of those pipes after replacing my turbo and when I pushed the accelerator I got a high pitch whine. It was one of the metal gaskets vibrating because it wasn’t tight.
 
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