What do these codes mean?

[BeetleCamry]

Hey guys, my CEL has been on for about 3 months now. My car runs fine, maybe a little less gas mileage, but fine other than that. I pulled the codes, and I know what they are, but what do they mean?

P0301-Cyl.1 Misfire Detected
P0302-Cyl.2 Misfire Detected
P0171-Fuel Trim,Bank1 System too Lean
P0134-O2 Sensor Circ.,Bank1-Sensor1 No Activity Detected
P0300-Random/Multiple Cylinder Misfire Detected
P1128-Long Term Fuel Trim mult.,Bank1 System too Lean
P1582-Idle Adaptation at Limit

I think some of it might be my coil pack? I have 126,000 miles and to my knowledge it hasn't been replaced. O2 sensor bank 1, where is that located, can I just remove it and clean it, or do I have to get a new one? Is this just plugs and wires? Any help is much appreciated. I won't mess up my engine if I continue to drive it will I? Is it possible that there are some hoses that have cracks in them causing these codes? Does anyone make a full hoses kit for the our beetles? Some of them are looking old and crackly, but I don't know where to get new hoses, once again thanks in advance

[SilverSportNOLA]

Sounds like you have a bad O2 sensor to start with, that should be the cause of the lower MPG. Not sure that would give the lean mixture problem .... chech vacuum hose to your fuel pressure regulator .... and if your car has the cloth covered vacuum lines, replace all of the cloth covered vacuum lines. Misfires could be bad coil, but could also be cuased by a lean or rich mixture. Start with one problem ... I would say O2 first, then clear codes and see what comes back.

[BeetleCamry]

OK, where is the O2 sensor located, can I buy this part online and install it myself? So install this, and then get the codes cleared out, and then see whats up? Sounds good!

[SilverSportNOLA]

That code is for your front O2 sensor. They are located on your exhaust. One is mounted after the cat converter, the other before .... I don't know exactly where on the 2.0L and you didn't list your cars year or engine type for me to look it up. They are not hard to change ... sometimes they need some persuasion in the form of a can of PB Blaster or Liquid Wrench. They are easy to mess up of you like touching things or drop them. If you are not a wrencher ... you might want to find some Water Cooled VW club in your area and find someone that could help you. They are plug and play ... watch getting the cheaper "universal" ones ... they sometime require wiring the plug harness from the old one into the new one ... another place you can blow it.

Also ... give us more info on the car ... Year, engine code, mileage. Some of your fuel problems could be due to trying to get 300,000 miles on a Fuel Filter. They should be changed every 40K ... and I wouldn't push them past 80K with the amount of dirt I see in mine when I change them every 40K.

[BeetleCamry]

OK my car is a 2001 2.0 auto. Its not a 2001.5 as it does not have the swivel cup holders, and the blinkers are still below the mirror. Can I reach the 02 sensor if I jack the car up? How much effort is required to change the fuel filter? I remember seeing a how to on it somewhere on the org. How much does an 02 sensor run from 1stvwparts? So replace the fuel filter and 02 sensor and clear the codes and see whats up? Can the codes be cleared by unplugging the battery, or do I have to do it via autozone? Thank you guys so much, my warranty is out and I can only imagine what VW would charge to do this.

P.S.-My car has cat-back exhaust, neuspeed p-flo, and has been chipped by upsolute. Dunno if this matters

[SilverSportNOLA]

The mods should not matter. Get the car on some ramps .... the plastic ones work well with our cars without damaging the bumper. You should be able to see the O2 sensors ... look at the one on the exhaust behind the Cat Converter ... so you know what it looks like, then look for one almost the same as that closer to the engine on the other side of the Cat from the rear one .... that is the one you need to replace. Before ordering parts, look to see if the wires going to it are in good shape .. not ripped, melted or such ... if all that checks out do the ordering. I don't know prices for them ... some are cheap and some are expensive.

Fuel filter is not hard to replace ... just a little difficult to figure out how to disconnect the hoses.

[BeetleCamry]

Thanks guys, VERY VERY much appreciated!!

[SilverSportNOLA]

Welcome .... I seem to be the only one here other than you .... who are the other Guys?

[vdubs]

BeetleCamry

I am not so sure it is the O2 sensors !!!!!!

First I would clean the MAF sensor which is located in the air intake tube, next to the air box/filter. VW had alot of trouble with these and cleaning it may not fix it but it is a cheap place to start. What happens is pollen, oil build-up, dust particles, etc. build up and burn onto the sensor hot-wires causing incorrect measurements. In most cases effecting air/fuel ratio resulting in number of items such as sputtering, wasted fuel, power loss and even automatic transmission shifting problems.

Go to your local auto parts store and pick up a can of CRC brand..part # 05110 Mass Air Flow Sensor Cleaner. $5.99 NOTE: Do not use any other cleaners such as carburetor, air intake cleaner or even brake cleaner as they can cause serious and expensive damage to the sensitive equipment, even the plastic.

Simple to do....Remove the air box lid. If you look up the tube you will see the sensor located just behind the part of the sensor that looks like a screen. Clean the electrical components, wire, and/or plastic housing using the CRC brand cleaner. It will leave no residue and dries quickly. Whole project should take around 10 minutes.

After cleaning it well....re-assemble and clear all the trouble codes from the control module memory. Now take the car on a drivability test and see it the MIL reappears.

[SilverSportNOLA]

This code:

P0134-O2 Sensor Circ.,Bank1-Sensor1 No Activity Detected

does not appear unless the O2 Sensor is dead or disconnected.

MAF could cause the Lean condition if it is malfuctioning ... if it is really bad the engine should run rich. I would start with the O2 .... a dead on give the ECU no information to adjust fuel mixture ... I know with a 1.8T that would richen the mixture ... but on a 2.0 ... not so sure.