Just bought my 1st Porsche... I already have a CEL!

[mkurdziel]

I just bought my 1st Porsche!!!! Its a 99 Boxster with 75k. I had to drive about 120 miles to get it. So on the return trip of 120 miles... Lets say 90 miles into it, the CEL comes on. I went to AutoZone and they coded it as P-1126 and P-0150. Could this be the O2 Sensor just needs to be replaced or did I just buy a car that is about to cost me 3k in the first week of me owning it?

I have done tons of research on this and from what I have read it could be the MAF or AOS or a a number of things...

Any help or suggestions would be appreciated...

Thanks

Matt

[Loren]

:welcome:

P0150 Oxygen Sensor Ahead of Catalytic Converter (Cylinders 4 - 6) - Intercore Short Circuit or Limited Voltage Increase

Possible causes:

- Oxygen sensor

- Wiring harness

- DME control module

P1126 Oxygen Sensing Adaptation Area 1 (Cylinders 4 - 6) - Rich Threshold

Possible causes:

- Intake air system leaking.

- Fuel pressure too low.

- Volume supply of fuel pump too low.

- Fuel injectors fouled

Very likely these are two separate issues.

Replace the O2 sensor on bank 2 ahead of the cat and reset the faults codes. Then see if the P1126 comes back - if does then you likely have an air leak.

[mkurdziel]

Thanks, I read somewhere that o2 sensors are about 130 each and if you replace one, you should replace them all. Pretty easy to do your self or expereinced mechanics needed? I am an average handy man around cars.

[Loren]

Thanks, I read somewhere that o2 sensors are about 130 each and if you replace one, you should replace them all. Pretty easy to do your self or expereinced mechanics needed? I am an average handy man around cars.

Sorry, I totally disagree.

Replacing all the sensors is just a waste of money in my opinion.

Who knows what caused this sensors to go? Did someone spill oil on it? Did a rock bounce up and damage it?

I have seen cars where one sensor was replaced and the owner did not have to replace another sensor during the time they owned the car.

Just my opinion...

[JFP in PA]

+1 on Loren's comments; far too many parts (O2 sensors and MAF units) get changed without doing proper diagnostics, only to be found not to be the issue......

[mkurdziel]

Thanks... I will keep this updated

[infocusf8]

Don't start replacing parts at random, you will only create a money hole that will cause you frustration as well. Porsche has developed a diagnostic tree that will isolate the problem so you replace the right part if needed. It may seem like it costs a little more at first to go this route but it will have you back on the road enjoying your car and not having a CEL come on again a few hundred miles after random replacement. If you want to do anything check your gas cap first. Is it sealed (three clicks minimum), is the gasket on it in good condition? I only suggest this because some times people don't tighten the gas cap after refueling and it will cause a CEL with emissions related codes.

[mkurdziel]

Update... I got a brake fluid flush, oil change and replaced the o2 sensor. We are looking good. Check Engine light is off. The mechanic that only does Porsches recommended that I consider getting an intermidate shaft bearing replacement. He nothing is wrong with the car, but Porsche made the 97-04 Boxster with poor intermidate shaft bearings. He showed me that they start to get dent and broken and shoot small metallic parts into the engine when they go. He told me that he has seen Boxsters do this at 40k and he seen people that have owned the cars with 150k with no problems at all. Since I bought this car used and dont truely know the history, should I consider this?

[logray]

The IMS bearing is a much debated topic on this engine.

As your indy said, some cars go kaboom (maybe 10% or less) and others (perhaps 90% of all cars) go on for their whole life without nary a problem.

If you don't upgrade the bearing with LN Engineering's ceramic hybrid you can buy a preemptive bearing failure monitoring/notification system from Flat 6 innovations. It's up to you whether you want to drive the car wondering if you are in the 90% or 10%.

http://www.flat6innovations.com/shop/product.php?productid=16285

[infocusf8]

I wouldn't go by percentages as, to my knowledge, there is no hard data to support the exact number of claims for failure or at what mileage. Porsche has some of the data for the motors they replaced but they have not released it. I bought my '99 with 74K miles and for another 10K miles tracked and AX'd it so it was driven hard. At 84K I decided I wanted to keep it for a long time and had the IMS and RMS replaced. I had the LN ceramic bearing put in because tests show that ceramics outlast metal 5:1. My OEM bearing showed some wear, a broken seal and smelled very burnt so it is hard to tell how much longer it would have gone. I made my decision, not based on fear of failure, but due to my wanting to give my car the best chance to survive so I can enjoy it. You should not rely on anyone else to make a decision such as that as it is an expense and it is your car.

[logray]

Certainly the percentages are just guesses, as no one has the statistics.

From http://www.lnengineering.com/ims.html:

"By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles* - resulting in a staggering 10% failure rate (called the L_l0 life)! *Assuming an average speed of 60mph in top gear."