Getting many different answers for why mycar is acting up

Hello, I have a 2001 vw jetta 2.0cl. the check engine light has come on and says too lean and cylinder 3 misfiring. now the many answers come because I have replaced to factory radio and people say that the radio was not correctly installed. The car seems to run fine still gets great gas milage and has get up and go. Now when I put the heated seats the lights will flicker. The light flicker to the beat of the radio. When i use my turn signals the radio will turn off then turn on again. After starting and the normal 5mph door lock will make the radio turn off and back on. When I have to use my breaks the lights will dim.

I look at your post, it is all over the map, with no clear connection of events and no clear report as to what has been done so far and no clear question. It is not a all unbelievable that you are not getting good answers, garbage in garbage out.

I also am going to question the radio install. It may be a high power thumping radio that takes a lot of power and it is stealing it from the parts of the car that make it go. It is also possible that when installing the radio someone messed up something, no connected to the radio, but close to it. It does really look like too much power drain on a circuit or a poor connection somewhere.

How much time was there between the misfire reading and when the radio was put in and when the lights and other things started happening? In what order die they appear. What if anything was done in response to the indication of misfire and lean conditions?

I would not rule out much else yet.

How about sharing with us the exact codes you got when they were read.  They should be in the format of [P1234]  

  Did whoever read the codes have a VAGCOM or a standard code reader? Only the VAGCOM (or whatever VW is calling their latest reader/ adjuster these days.

There are two issues, the CEL and the electrical problems.

The CEL is warning you about the too lean condition and the misfire. These have nothing to do with the lights/seats/radio problem. The too lean condition could be caused by a bad O2 senor, but I suggest you have the sensor tested before you replace it. The misfire could be caused by many things. You need a mechanic for these.

As for the other problems, do these symptoms manifest themselves when the radio is off? Did you install an amplifier and/or a subwoofer when you replaced the radio? I would want to know what happens when the stereo system is completely shut off. This may provide important clues to the cause of the problem.

I used a standard code reader. i don’t remember the actual code, but VAGCOM seems to be what I need to look for in a mechanic. To answer the other questions, Very shortly after getting the radio installed the check engine light came on, 1st it was for the water pumb (or that’s what VW service center told me), then about 3 weeks later the light came on again and that is where I am now.

For the radio: Each speaker has an amplifier atached. I tried to get a set of infinity speakers installed and couldn’t. No subwoofer. I have never tried with the radio off but the volume all the way down. The only difference is the flickering with the beat.

thank you for trying

You don’t want to clean your post up?

If you couldn’t install Infinity speakers, what did you install? I replaced the factory speakers in my Acura with Polk speakers, and it made a world of difference, so I can understand why you did this.

Each speaker has its own amp? Wow! What’s the wattage output of each amplifier?

I just want to make sure I have this right. You have a head unit (radio/CD/MP3 player), four separate amplifiers, one for each channel, and four speakers. Is that correct?

I think the amplifiers might be drawing more current than your battery and alternator can provide. You can test this be removing the radio/amplifier load from the system and seeing if the lights still flicker.

Remove the fuses, or do whatever is necessary, to make sure the radio and all amplifiers are completely OFF, then drive the car and see how the turn signals, seat heaters, door locks, etc, operate.

Post back here after you’ve done this.

I agree with mcparadise. These are two separate issues. The lean condition and misfire could also be caused by a clogged fuel injector. I’d hope your mechanic will look at the #3 fuel injector as suspicious.

As far as the electrical problems, have the alternator checked. There is a serious voltage drop happening any time something moderately powered is used, like turn signals and brakes. If the alternator is tired, and not generating the proper amperage, the system will react by dropping voltage as the power demand goes up.

With all the interactions I would look for a poor ground connection. Do the amplifiers etc. have their own chassis ground wires or are they tied to existing ground lines?

May 11, 2009 Update to above. I went to my mechanic and got a reading. Changed the ECM and the radio was bad. I replaced the radio and all the corky things have stopped. Aside from the radio, the alternator wasn’t charging the battery, so I replaced that. I have replaced the O2 sensors and have switched to 93 octane gas. I cleaned the MAF and cleared the Check engine Light. The longest it has been off but still came back on 2 days later and reads P1707 Too Lean. What should I look at next to avoid changing the EGR and or the MAF sensor?

Do you by any chance have a K&N or other type of aftermarket air filter that needs oil on the element. The oil gets on the MAF sensor and causes it to mis-read.

As for the radio, was it defective or was it a very hi watts amplifier. I know the argument that stereo shops use for the greater linearity of hi powered amps, but they forget to mention the increase in junction noise they cause. In a car, anything over 50 watts per channel is too much.

Why did you change the engine computer? Just a suspicion? You need to DO some troubleshooting. Several people have suggested areas to troubleshoot. Changing suspect parts is NOT troubleshooting.
Now, the EGR valve and MAF sensor are on your suspect list. Why? If you suspect them, or any component, test and check them. The instructions are in any repair manual (Haynes, Chilton’s, etc.).
Are you a dedicated parts changer, or, are you willing to do some troubleshooting? Which way will fix your car?

Somebody wired a stereo to an inconvenient power sourse behind the driver’s door on an old Buick Skyhawk. Loosely connecting it to the power wire going to the fuel pump. Radio? No problem. Fuel pump? Quit working after a while until the radio wire was taken off and the connection redone. I hope it isn’t the problem on your car. Until a mechanic works on it, you will have a large variety of answers.

the only thing after market on this car is the radio.

Great, thanks, now you do know I have a VW Jetta and not a Buick Skyhawk. How does this compair in anyway? Plus the radio problem is fixed. The problem now is “too lean” and the check engine light.

ECM was changed because my mechanic said it was a read out that he got. He said he can’t touch my car until it is fixed. That is why I changed the ECM. Now the update that I wrote on 5/11/09 said “I replaced the radio and all the corky things have stopped.” I did that because the radio was bad and was replaced by the store I purchased it from. The only other suggestion was to look at the O2 sensor. I did that because when I checked them they were bad. I didn’t realize I had to explain how I got to the point which made me change the O2 sensors. And last I checked the “check engine light” means emissions and don’t O2 sensor have something to do with emission? YES IT DOES!!!

Now I am laughing because my question was “What should I look at next to avoid changing the EGR and or the MAF sensor?”

You answered with “Now, the EGR valve and MAF sensor are on your suspect list. Why? If you suspect them, or any component, test and check them. The instructions are in any repair manual (Haynes, Chilton’s, etc.).
Are you a dedicated parts changer, or, are you willing to do some troubleshooting? Which way will fix your car?”

Let me second circuitsmith. Check the ground connection at the battery, the engine and the chassis. If you have a multimeter, turn on the headlights and test for a voltage between the battery negative terminal and the chassis/engine block. There should not be one. Do the same between the battery negative terminal and the radio ground.

A seriously bad ground will cause the voltage between the positive battery terminal and “ground” to vary depending on how much power is being pulled by loads like the radio, heated seats, etc if they are connected to the battery through that ground connection. If the drop across ground is too great, it might affect any electrical device in the car including the computer and the ignition.

In any case, I’d find and fix the electrical problem with the radio, then see if the fuel mixture/misfire problem goes away. Who knows? You might be lucky.

2/18 or 19 might have been a good thing, but 5/12 not helpfull at all. As i stated just below circuitsmith 2/18 post the radio has been fixed and all the corky problems have stopped. Now I am still left with a too lean reading.