Failed MA emissions inspection for P0673

Hi all,

I'm a brand new owner of my in-laws' 2002 Jetta, and I just failed the Massachusetts emissions inspection, as the OBD test returned code P0673. I've looked through the glow plugs 101 thread and I feel that doing the diagnostic steps listed there for the #3 plug and the wiring harness are within my very limited mechanical ability, but I had a few questions that I was hoping someone could answer; I couldn't find any other threads directly answering these questions:

1) I am under the impression that replacing the glow plug or spraying DeOxit may truly solve the problem, but it won't clear the code. Does this mean that when I get the car re-inspected, it will still throw the code? If so, are there any straightforward ways of clearing the code myself?

2) A bad glow plug or harness doesn't seem like an emissions violation to me, but I've read that the MA emissions test recently changed, and any OBD fault will cause an inspection failure. Anyone know if this is indeed the case? I ask in part because the car has been through 7 upstate NY winters and has never had the exhaust system touched, so I figure we're in for a big repair in the coming year or so.

3) For full disclosure, the check engine light has been on for a while. My father-in-law had the code read a month or so ago and it indicated a bad thermostat. We're planning to get that replaced soon anyway, and so maybe if I can do the glow plug service myself, the shop will just clear all codes at once.

Thanks in advance for any advice!

It is easy to clear the code after you correct the problem. You can use a code reader or I believe places like auto-zone will use a code reader to do it for you. The code will return though if the problem is not fixed. I would buy a code reader that can erase the code if I were you. They are cheap and it is handy to have.

You are not that far from Chris ("MrChill") Hill's shop in Braintree, MA in case you get stuck and need help. He is one of the best TDI mechanics in your area.

You can read up on the Mass. DEQ web site on vehicle testing and how the OBD II test works. I have it in Virginia (Northern Virginia, to be specific). The CEL must work (light on key on), the light must not stay illuminated with the engine running and NO CODES must be stored in memory, period, and all (except one may not be reset) rediness codes must be set to "ready" for the car to pass. If the readiness codes are not set to ready, the car is rejected from testing (this is not a test failure) and you will be asked to bring back the car later to see if the codes reset to "ready". Clearring the OBD II codes from the ECU sets the indicators to "not ready" and you have to drive a while to get them to reset, and if there is a problem, the CEL will come back on and a code get stored. Just clearing the code and getting an inspection before the light comes back on does not work if there is a problem.

The easiest thing for you to do is remove the glow plug connector and check each plug for contimuity and any bad ones will be open (infinite resistance). Replace these (about $22 each). You must use a scan tool to clear the code after that. If all plugs are good, it is some other issue. Bad plugs are the most common reason for the GP code, though.

--Nate

Mr. Chill

owr084 said:

You are not that far from Chris ("MrChill") Hill's shop in Braintree, MA in case you get stuck and need help. He is one of the best TDI mechanics in your area.

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Does MrChill work for a dealer or himself? Is he able to do work on TDI like cleaning turbos, manifolds and just plain upgrading things on a 1998 Jetta TDI??? I have a guy that fixes my car when its broken but he is not a real Jetta TDI mechanic....It would be nice to go to someone who is very familiar with TDI etc.......in fact my car also failed the emissions and it only failed because the garage computer could not link up to my OBD so now I need to get the OBD fixed.....This emissions stuff what a pain in the a**.....Do you have contact info for mrchill I am in RI which is a bit of a drive away but not that bad in a diesel!!

Chris Hill runs Kraftwerke Autotechnic... http://www.kraftwerke1.com/

Yes, he's a "real" TDI (and other) mechanic... one of the very best!!!

If you want to make his acquaintance, check around the Eastern USA forum to see when there's a Get-Together in the area... (I believe there will be one of the famous HouseOf5Garages events new-year's day... in East Hampstead, NH...) he usually shows up - as do many of the other local (and not-so-local) gurus...

Yuri


PS: he's definitely worth a long drive...

AlanH70 said:

Does MrChill work for a dealer or himself? Is he able to do work on TDI like cleaning turbos, manifolds and just plain upgrading things on a 1998 Jetta TDI??? I have a guy that fixes my car when its broken but he is not a real Jetta TDI mechanic....It would be nice to go to someone who is very familiar with TDI etc.......in fact my car also failed the emissions and it only failed because the garage computer could not link up to my OBD so now I need to get the OBD fixed.....This emissions stuff what a pain in the a**.....Do you have contact info for mrchill I am in RI which is a bit of a drive away but not that bad in a diesel!!

Click to expand...

Even from the farthest Southwest corner of Rhode Island to Braintree MA is less than 90 miles. That's Just around 2 gallons of diesel - a drop in the bucket. If you need more convincing of Chris's abilities, just do an advanced search on his posts.

I run into faults with glow plugs all the time. If the glow plug tests good then its your glow plug harness that needs to be replaced along with the relay, (if equipped). The fix isnt cheap if you go to a dealer but i dont know what independent shops charge.

You can replace the GP's yourself, and the buss if need be (probably), then clear the codes and verify a state of readiness at your OBD port with VCDS. Or you could take everyones advice and go see MrCHill. Besides what has been stated already he also own's an A3 that you may get some ideas from. It would also be a great time to have him do a look over to point up some items you may want to address in the future.