2001 VW Passat Oxygen Sensor Check Engine Light

Can't tell from here, but I would look for a bad wire, or connection or a bad sensor (who knows the new one could be bad) or the new computer could have been bad.

Reply to
Joseph Meehan
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Hi. I'm having a problem with my 2001 GLS Turbo Passat. A few months ago, the check engine light and Emissions Workshop message came on. The first VW dealer we took it to said it needed a oxygen sensor, mass air flow sensor, and something else I can't remember. Seemed odd to me that three parts would fail at the same time, so we took it to another dealer. They said it was a faulty computer, which was covered under warranty. They replaced it and everything seemed fine, for a little while. A short time later, the check engine light came on again. Took it to Autozone to see what code was being returned. Said it was the oxygen sensor in bank 1. Having lost confidence in the VW dealers, took it to a local, trusted garage. They too got a bad oxygen sensor code. They replaced the oxygen sensor and reset the light. After about 30 mins of driving, the light came back on. Took it back and they hooked it up again. Still said bad oxygen sensor! Not sure what to do next. The car won't pass emmisions with the faulty code. Is this a known problem? Is there some trick to resetting the code correctly? Any advice would be appreciated. Thanks!

Reply to
damonl73

What were all the fault codes present. I bet the oxygen sensor had a code something like "no activity detected" which is the most miss diagnosis fault around. Well it could be a faulty oxygen sensor, but it's more likely a lean condition in the engine. See, when a engine goes lean there just isn't enough oxygen in the exhaust for the oxygen sensor to produce a voltage. So, the ECU thinks the oxygen sensor is faulty. Whoever looks at your issue, they need to use their diag skills better and see how the engine fuel trims are. My bet is on a vacuum leak... so take a close look at all your hoses on the intake manifold, especially the one located between the coolant bottle and intake manifold! Don't just look at it but use your hand to inspect it for splits and cracks.

Reply to
Woodchuck

diagnosis fault

likely a

voltage. So,

inspect it

Reply to
damonl73

diagnosis fault

likely a

voltage. So,

inspect it

Reply to
damonl73

That's your vacuum leak ... I think you owe Woodchuck a beer.

Reply to
Erik Dillenkofer

Many thanks to everyone. I really appreciate you sharing your expertise. If you ever find yourself in the Lehigh Valley, I'd be happy to buy you a beer. You probably saved me some considerable time and money.

Dam> That's your vacuum leak ... I think you owe Woodchuck a beer.

inspected

coolant

Reply to
damonl73

I recently had the exact same problem on my '99 Jetta GL (A4) POS. I had both the O2 sensors replaced and the computer reset. The light came back on after a couple of days. Finally paid the $500 and had the mass air flow sensor replaced. No problems with engine lights since and its been about 9 months.

"Is this a known problem?" VW and their crappy cars are a known problem.

Reply to
Lophophora

Thanks for everyone's suggestions. I am going to start with the hose and hope its not any of the other sensors.

Dam> On 13 Dec 2004 18:46:26 -0800, snipped-for-privacy@yahoo.com wrote: >

another

sensor

Reply to
damonl73

Thanks for everyone's suggestions. I am going to start with the hose and hope its not any of the other sensors.

Dam> On 13 Dec 2004 18:46:26 -0800, snipped-for-privacy@yahoo.com wrote: >

another

sensor

Reply to
damonl73

Paid for a MAF, they are under warranty for 7years/70,000miles BTW, which engine do you have?

Reply to
Woodchuck

The 2.0L. I was over 70K.

Reply to
Lophophora

Hey, I'm from the Lehigh Valley (currently in Berks County), and I have a 2001 Cabrio who's check engine light keeps coming on. I forget what they (Vision VW) said the code said was leaking but they couldn't find any leak - they also said that if could be caused by putting gas in while the car is running if that helps at all - but of course within half hour of driving after getting the car back the light came back on. Haven't done anything about it yet. Anyway, does that quailfy me for the free beer??? :-)

Teri

Reply to
teri

I just joined the group and missed this discussion, but it sounds like one I wish I could have read. I have a 2001.5 Passatt 1.8T and am having an idle problem. At time it's fine, but at other time it acts like it want to die when idling. Gas mileage is still good and it runs fine once it gets rolling. Someone told me it might be the Oxygen sensor. Can someone tell me where it's located on this engine? Also, any other ideas what the problem might be?

Thanks allot!!

Jack

Reply to
Jack Dotson

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