# Jetta 2.0 2002 misfire problem



## rfdnd (Mar 8, 2011)

EDIT : video of the misfire issues







Hello,

Just bought a 2002 2.0 Jetta GLS. It was driving fine before but I could notice a slight hesitation past 3000 rpm. I scanned it for trouble codes and got two about o2 sensor and cyl 3 / 4 misfiring and random/multiple cylinders misfire. 

Three days ago it rained/snowed a lot. I used the car for about 30 minutes and parked it. 

Yesterday morning while I was going to work, it began to hesitate to the point that it could not reach 4000 rpm. It is reving so slow, like it swallowed water. The check engine light is blinking. When I depress the throttle, it backfires and it smell gas. A backfire even blew the piping before the catalytic converter!

When i press slightly on the throttle, it revs normally to 3000 rpm then it stutters badly. 

So I took off the air filter and dried it. I removed the coilpack and noticed a small hairline crack. Did the jbweld trick and put everything back on.

This morning when I started the car it was driving fine but after a few minutes of driving it began to hesitate so much that I could not make it to my job. The jb weld on the coilpack is still solid.

I replaced the spark plug wires, same problem.

What should I check next? The spark plugs seems to be the next logical step... Or is there anything else ?

Thanks!


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## nigelrmccoy (Jun 11, 2010)

I too am having very similar issues to this as well. I got a new coilpack and 2 new spark plugs have been put in (waiting on tool to remove 2 inner spark plug boots) and between 1-2000rpm between 1/2-full throttle it just chokes and chokes, and above 4000 too. Then every once in a while it will get really bad and shake, with lots of gas in the exhaust.. MAF?


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## rfdnd (Mar 8, 2011)

Can a faulty o2 sensor cause hesitation, misfires and stalling?


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## ovdvdub19 (Jan 15, 2010)

rfdnd said:


> Can a faulty o2 sensor cause hesitation, misfires and stalling?


Im pretty sure it can because my vr was doing the same, so I replaced the o2 and all was good. But my aba turbo slowly goes lean at stop lights and missfires occasionally so i figured it was a slow acting o2 so i installed a new one with no change


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## brooks4533 (Nov 28, 2008)

Just had the same problem with cylinders 1 and 2 misfiring. Ended up being the precat o2 sensor. I believe yours is the post cat o2. It fixed the misfire but Now it looks like my converter is fried. I have a 99.5 jetta 2.0l with 127k miles. I had the exact same symptoms as you did.


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## rfdnd (Mar 8, 2011)

Just scanned it and cleared trouble codes : I had the following : 

P1118 - Oxygen (Lambda) Sensor Heating; B1 S2: Open Circuit
P0141 - 35-00 - Please Register/Activate (O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2))
P0300 - 35-10 - Please Register/Activate - Intermittent (Random/Multiple Cylinder Misfire Detected)
P0304 - 35-10 - - - Intermittent (Cylinder #4 Misfire Detected)
P0301 - 35-10 - Please Register/Activate - Intermittent (Cylinder #1 Misfire Detected)
P0303 - 35-10 - Please Register/Activate - Intermittent (Cylinder #3 Misfire Detected)
P1296 - 35-10 - - - Intermittent Error in Mapped Cooling System (check Temp-Sensor and Thermostat)
P0302 - 35-10 - Please Register/Activate - Intermittent (Cylinder #2 Misfire Detected)

I cleared them all but this only this one came back immediately : 

P1118 - 35-00 - Oxygen (Lambda) Sensor Heating; B1 S2: Open Circuit


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## rfdnd (Mar 8, 2011)

Ok, went to the garage, had the spark plugs and pre-cat o2 sensor replaced.

Check engine still on, I scanned the car at home, got the following : 

P1116 - 35-10 - Oxygen (Lambda) Sensor Heating Bank 1 Sensor 1: Open Circuit

Why the other sensor is giving me codes ?

Yesterday I checked the wiring and it was okay... don't really know what to do next.

At least no more misfires.


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## rfdnd (Mar 8, 2011)

Still misfiring today! Crap!


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## nigelrmccoy (Jun 11, 2010)

ya.. so i eneded up replacing all the spark plugs and the coil pack. first start went well, and there was little to no misfiring during part-full throttle. idle is still a little rough tho. And then this morning, on my morning commute, it started again.. it really sucks having 3 cylinders working half the time. Also, it was rainy for the past 2 days here too, so I don't know if thats causing any trouble. Now i'm thinking either:

-mass airflow sensor
-any of the 02 sensors
-cam/crank position sensor
-plug wires
-ground issue


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## rfdnd (Mar 8, 2011)

When I had my TDI, MAF went bad and it didn't even throw a code. I replaced it and it was fine.

After work I'm going to clean the MAF and give it a try.


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## rfdnd (Mar 8, 2011)

Problem is worse than ever. It misfires so much that the car is not even able to get its rpm higher than 1000rpm.


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## digraph (Jul 23, 1999)

is P1116 still there after clearing the codes?


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## rfdnd (Mar 8, 2011)

Yes P1116 appeared right after pre-cat o2 sensor was replaced. I cleared the code but it came back immediately.


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## boobert (Aug 11, 2001)

I have replaced 2 or 3 O2 sensors on various 2.0s. I wasn't getting misfires for any of them. Precat or postcat. I would look some place else for the problem. I think but can't remember because it was so long ago when my maf went it may have showed a misfire. This was back in the day when the car was new and vw was shipping them with bad sensors. I also remember there was a tsb to update the ecu to fix some problem with the car reading sensors incorrectly so who knows. There is a way to test the maf I would search around for it.

The only time I've had a 2.0 run the way you describe is when my wifes 98 beetle sat in the garage all winter. I gave the car to a friend though and don't know what was fixed on it. I do know it was fixed and ran fine.


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## rfdnd (Mar 8, 2011)

That's what I though. I had o2 sensor related codes with my previous mk4s but they never caused misfires.

I called the nearest VW dealer, 330$ for a new coil and 126$ for OEM spark plug wires. 

Guess I know what I'll be doing this evening hehe.


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## rfdnd (Mar 8, 2011)

Added a video of the issues.


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## rfdnd (Mar 8, 2011)

Installed a brand new coilpack, all is good now !

JB Weld doesn't fix everything unfortunately 

Thanks !


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## boobert (Aug 11, 2001)

Cool.


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## jcasti-58 (Mar 4, 2011)

I'm having the same issues but only on cyl #2, and is the same that the video, I replace all spark plugs, does a bad coil cause problem only in 1 cylinder?

or is more probably that the spark plug wire be bad?


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## lunchbox92 (Sep 11, 2010)

a coil pack is a connection point for all your plug wires, yes 1 connection point can go bad on a coil pack.


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