2000 Passat surging, "emissions workshop" message

[mel2000]

I have an ongoing problem with my 2000 Passat 1.8. The "emissions workshop" message comes on shortly after I start driving the car. Also, when the car is in Drive and I am stopped, the car surges repeatedly and the idle jumps up and down. If I let up on the brake and re-brake, the surging decreases, then builds back up again. The car won't surge like this in Park or Neutral. Now I put the car in Neutral when I'm at a stoplight. There is also a strong smell of gas in the exhaust. Don't know if that is related.

I have had the vacuum hoses replaced. No improvement. I had the 02 sensor replaced. No improvement. I made the mistake of not getting a copy of the computer codes from first scan (independent mechanic, not VW). Had it scanned again yesterday. This time there was one code, P1128.

It's probably obvious from my post that I don't know much about cars. Has anyone had similar experience with a Passat and found the problem?

Thanks-

[bahnfire]

From what I understand based on other posts, the P1128 error boils down to an air-fuel management problem. The code can be triggered by

a) a loose gas cap
b) a clogged air screen in the air box (below the air filter catridge)
c) an old air filter catridge
d) a vacuum leak
d) a bad mass air flow meter
e) bad 02 sensors
g) an exhaust leak

among other things I think.

I'd start with the first three items for a potential cheap fix. The only tools you will need will be a screw driver to remove the air screen for inspection. If you end up going into the air box, you may want to change out the air filter while you are there and clean off whatever is on the air screen. Would be good to do both anytime your in there. A clogged air screen was my P1128 trigger.

I've found that vacuum leaks tend occur at vacuum line connection points. Make sure the connection points are secure and look for cracks (paying close attention to the connection points). If you see a crack at a connection point, you may be able to snip a little bit off the end and reattach for a fix.

Your mass air flow meter may or may not be under recall. Call the dealer and check, can't hurt. If not, they can be found on Ebay at resonable prices relative to the dealer. No tools required to remove and install.

O2 sensors can start to go lazy and/or get contaminated (engine coolant can really do a job on them). I think there are two in our cars, one upstream of the catalytic converter and one downstream. I think a wrench will be all that's needed to remove them but getting to them is a little work.

Exhaust leaks may be able to be patched depending on where there are. Cold weather helps reveal them.

Good luck and I hope this helps.

FYI - Autozone will scan check engine lights for free.

[mel2000]

Wow-this is great info. Thanks.

[limacina]

I signed up for this page for that very reason in my 01 passat 1.8t
Check out http://www.taligentx.com/passat/main.../throttlebody/
He gives great instructions on throttle body cleaning and potential carbon build up causing the rough idle

[veedubmechanic]

VW covers mAF sensors on 99-01 for 7years 70,000 miles. not recall just extension of warranty.

[limacina]

veedubmechanic, Great info for most people viewing this page. My wife commutes 85 miles a day. we're touching on the 100,000 mark hoping to go to 200,000 so I'm on my own on small repairs. I did break down and pay to do the timing belt. Mostly because of the time it would have taken me as an ameture

[boschmann]

The cars also had problems with the larger diameter vacuum hoses hidden under the intake manifold. They get soft & colapse or perforate.

[b1udrk88]

I had a similar issue. Found out it was the bypass valve and it's very easy to check. My valve was crapped up and wouldn't open when the accelerator was depressed. You can check this, it's very easy to take off and replace. Suck on the top (with your mouth like using a straw) and the valve should open easily. If not, replace. Cost is pretty cheap and labour is cheap too. Pretty easy to get to on mine (2000 Passat 1.8T)...front of the car...black rubber piece. Replaced it with a Bosche one for about $40. Never seen "emissions workshop" since.

[antileet]

I am having a simulair problem that started after I changed out a very old filter (just bought the car) with a K&n airfilter.

[mel2000]

My problem turned out to be the Mass Air Flow Sensor and one of the vacuum lines. I get the car car back today and i willl update on how it's running.

[antileet]

my problem got worse today and the car stalled out twice so I took it back to the dealership where I bought it and am now hoping for the best

[raakcc]

I had mine fixed too. Maf and broke vac hose on throttle body. The car runs like a champ and it seems like there is more boost. I can send pics of the hose that was broke if needed.

[sgbennett]

I have a similar emissions workshop problem. A few recommendations were to check the bypass valve, the air box and the air screen. Where are all of these located?

[Helgas mom]

I have had the same problem wiht my 2000 Passat with 111000 miles. I have owned this car for 6 years and I love it but for the past 2 years I have had the emmission workshop light off and on. I recently spent over $400 on hoses and such at an independent shop but tired of the excuses when the problem kept resurfacing. I took it to the dealer and they are totally stumped. The service manager with 27 years experience with VW spent over 10 hours at no charge on top of performing a repair that did not work, and could not come up with a cause. He swears that the car is in great shape but the light won't go out and stay out. He did blow 100 psi air through the engine and the light went off for 3 days which is longer than any other time but it came back on today. I really like this car but it makes me nervous now.

[limacina]

We were so very close to a cure on my wifes 2001 passat with an independent repair guy; then she got hit on the highway and totaled it. The accident went so well, we ran out and bought a 2006 passat.
Back to your problem...
I had no luck nor confidence in local dealership mechanics. I found a local guy, specialist in europian sports cars, Sports imports of Falmouth, ma. Suprizingly he was pretty inexpensive compared to the dealership and he came thru with results. And most of all, he knew what he was talking about and could explain it to you. If a mechanic can't explain the problem to you, it's because he doesn't understand it fully himself. Do not blame yourself for not understanding him.
Read the posts here and take all of the problems in. We were clearing another set of codes everytime we brought it in. The were multiple problems, not easy for an average mechanic to fix. VW tendsrto throw out an alarm code for the slighted issue, where cars companies of less quallity may have a lower standard for the code.
Vacum lines were with the effort, a good mechanic has a smoke tester to look for leaks, the coils still seem to be a defect here and need replacing often, not sure how often though.
Helgas Mom, These issues and the emisions workshop will not usually leave you in the side of the road with a dead car. At most, you won't get an inspection sticker and you poluted the air a little more.
Go through this web site and jot down a list of known issues, check them off as mechanics find the issues. Find a really good mechanic specializing in european cars. make sure they're not a guess and replace parts kind of place. That works with a GM or honda but costly with a Passat.

Best of luck everyone, I'll be back here looking for help when the '06 give us issues.