'01 Jetta Sluggish, Gas Smell - PeachParts Mercedes-Benz Forum

gmercoleza · #1 11-21-2005, 04:00 PM

I know it's not a mercedes, but... It is German, does that count?

Wolfsburg edition, it's running somewhat sluggish and is giving off a distinct smell of gas from the exhaust. However, no trouble codes.

Anyone out there have a Jetta or familiar with one? My first guess is O2 sensor. How do I check it? Should the voltage be about .45 at idle warmed up?

TIA

manny · #2 11-21-2005, 05:30 PM

[QUOTE
Anyone out there have a Jetta or familiar with one? My first guess is O2 sensor. How do I check it? Should the voltage be about .45 at idle warmed up?
TIA[/QUOTE]

Had a 1997 once.
I would suspect a faulty O2 sensor to give you a CEL & set a code.
If you want to check the sensor, warm up the engine, backprobe the signal side of the O2 connector & you should read an oscillating voltage of @ 0.1 to 0.9 volt.
Remember, a 4-wire sensor has 2 ground wires, 1 - 12 volt ( heater ) wire & 1 signal wire.

gmercoleza · #3 11-21-2005, 07:11 PM

OK, I failed to mention the CEL came on briefly 2 or 3 times, but is not currently lit. Anyway, figuring the code would be stored in memory, took the car by Autozone where they hooked up the scanner and retrieved a bank 1 oxygen sensor code. A universal sensor was $60 (supposedly the wiring should match right up, but it has to be spliced on).

Question: which one is bank 1 oxygen sensor? Do I have to crawl under the car or is there access to it from somewhere in the cabin (i.e. under the carpet)?

Thanks!

dkveuro · #4 11-21-2005, 07:41 PM

Quote:

Originally Posted by gmercoleza

OK, I failed to mention the CEL came on briefly 2 or 3 times, but is not currently lit. Anyway, figuring the code would be stored in memory, took the car by Autozone where they hooked up the scanner and retrieved a bank 1 oxygen sensor code. A universal sensor was $60 (supposedly the wiring should match right up, but it has to be spliced on).

Question: which one is bank 1 oxygen sensor? Do I have to crawl under the car or is there access to it from somewhere in the cabin (i.e. under the carpet)?

Thanks!

Bank 1 is the #1-3 on a V6 or 1-4 on a 4 banger.

What motor has it got....4 or 6 ?

gmercoleza · #5 11-22-2005, 08:38 AM

This is a 1.8 turbo 4-cyl. I got the O2 sensor out last night but noticed it is a 5-wire. The generic I have is only a 4-wire. Looking online, noticed that this 5-wire type is something called "broadband." Anyone ever heard of these? Is there any way I can adapt the generic 4-wire to substitute in its place? What is the 5th wire for? The reason I ask is that going with the generic sensor will save me about $150 + tax.

yal · #6 11-22-2005, 09:32 AM

Where the heck are you ordering these sensors? Just go online. The bank 1 sensor which is before the cat is like $50 online. The bank 2 sensor post cat is about $90. Both OEM Bosch.

Go to fastlane part shop above or go to...
http://www.alloemcarparts.com

3POINT · #7 11-22-2005, 09:33 AM

this o2 sensor is known as a nerst o2 sensor and uses a different concept of reading the o2. it uses a pumping cell in the sensor to pump o2 into a chamber and compares it to the cars exhaust.DO NOT try to instal a 2 wire conventional o2 sensor you will have more problems and mil lghts on. these cars had several problems such as the vaccum suction pump plugging up with carbon. it sits ubder the intake manifold(not fun to cahnge). also if the turbo boost valve leaks you could have vaccum leaks.It sits at the top left side of the engine with a vaccum hose to hit. check with vaccum gauge. also checkfor any other vaccum leaks. I changed many of these o2 sensors due to 'sporadic no response' codes. Are you sure it has 5 wires ? a conventional one will have 4 ,2 for the heater circuit and 2 for the sensor. the nerst one uses 6 wires.