help, high emmisions!

[Richard_Hamilton]

A proper diagnostic check is the way to go. You have already wasted far more than the cost of a check on two oxygen sensors you didn't need. No point in throwing more parts at it, in the hope you are going to fix it, or bodge it temporarily to get through the test. You could even get a clone Durametric for about £30, which will do the job in your case.

As an example, I know from personal experience that a bad MAF will not show up on an OBD2 tester. It will give P1126/8 or P1123/5 codes, which a generic tester won't read. And if the MAF is over 50,000 miles old you are living on borrowed time, despite Porsche's quoted life of 100,000.

Just my 2p's worth.

 

[Glyn]

Box986 - youre running around in circles and guessing what the problem is, without codes you are simply throwing money and time at a fix - this could even be a faulty temperature sensor - If the sensor sends a "Cold" signal (even when hot)to the ECU it will enrich the fuel/air ratio, Why waste time and money trying to "con" the MOT test - you need to fix the problem.

 

[Motorhead]

Just a question Glyn.

Is the temp sensor incorporated in the MAF? In which case just cleaning the MAF won't have any effect if the temp sensor has failed.

All the more reason for a definitive diagnostic check.

Jeff

 

[box 986]

so should i still just buy an maf? the car has 71,000 miles on it. i finally found someone with a durametric. i'm going to him tomorrow. i hope he'll see what the problem is since i dont have a cel.
thanks for the tips guys, i'll keep you posted

 

[Motorhead]

Ian,

I'd definitely hold off on changing anything else until you've had the diagnostic check, otherwise you could unnecessarily be wasting even more money.

Hopefully, the chap with the durametric has experience interpreting the responses for your 2.5 Boxster. If you need help, I'm sure that there are others on the forum but Richard Hamilton is a very useful source.

Jeff

 

[Richard_Hamilton]

If you can get the fault codes, I can email you the diagnostic troubleshooting sheets for them.

RoW (inc UK) 986's and 996's with mechanical throttle, like yours, use Bosch Motronic 5.2.2 engine management. These are set up differently to US cars, in that it will not throw a CEL for a faulty MAF. On USA cars, you just have to f@rt, and the CEL comes on!

Jeff - the MAF measures the air flow and inlet air temperature. Water temperature is measured by a sensor on the water pump housing, and the oil temperature sensor is incorporated in the oil level sensor.

 

[tscaptain]

ORIGINAL: Richard Hamilton



RoW (inc UK) 986's and 996's with mechanical throttle, like yours, use Bosch Motronic 5.2.2 engine management. These are set up differently to US cars, in that it will not throw a CEL for a faulty MAF. On USA cars, you just have to f@rt, and the CEL comes on!

Jeff - the MAF measures the air flow and inlet air temperature. Water temperature is measured by a sensor on the water pump housing, and the oil temperature sensor is incorporated in the oil level sensor.

[]

 

[Tony M]

There is a Catalytic cleaner solution called Cataclean that worked on a friends car when it failed on emissions.

If you Google the name, you can judge for yourself if you think it is going to work.

It is not a huge investment to buy a bottle and may do the trick !

 

[box 986]

the machanic did a diagnostic check and there were no reported faults!
I hope he has the right equipment but he said that he did many porsche checks with it and that usually a fault comes up if thereis one. now he noticed that on startup and under hard acceleration the car seems to emmit some white smoke. he said that is usually a sign of a failing air / oil seperator. I'm gonna go ahead and buy one I think, fingers crossed! I dont know if i should just get an Maf as well though, I think Ill start with the AOS first

 

[Richard_Hamilton]

On DME v5.2.2 you really need a Porsche tester to read all the fault codes. That is because it is not OBD2 compliant. Later cars use DME v7.2 and v7.8 which is compliant, hence most generic testers work OK.

What a generic tester MAY do is read sensor outputs for the mass air flow, and possibly air inlet temperature. For your car, it should be around 15 kg/hour at idle, and rise proportionally as you increase the engine speed. This would at least give you an idea about whether the MAF sensor is working properly or not.

White smoke is often caused by a failed air/oil separator. A good check is to remove the inlet hose to the throttle body, open the butterfly, and peek inside with a torch. If the inner surfaces are glossy with oil residue, then it is a good sign the AOS has split inside.

 

[Glyn]

Box986 - i dont think there is any helping you, despite all the advice you have had you are still throwing time and money at the problem hoping you get it right, cant understand why you just dont get the codes read by OPC and fix the issue, however its your money and time but your going to find your Boxster a very expensive car to run if you tackle issues this way

 

[box 986]

the problem is i cant find someone with an approved porsche tester in my area. as i said, nothing showed up on the mechanic's durametric.
Richard Hamilton, my mechanic removed the throttle body in front of me and it was very oily, a lot of residue inside .
I am going to be abroad this coming week so i will have to tackle the issue when i come back.
I was sort of releved to see that the throttle body had oil residue inside, maybe the AOS is the clprit then.
fingers crossed for when I change it, i will keep you posted

 

[Richard_Hamilton]

It sounds very much like the AOS then. They aren't too expensive (£66.28+VAT), and relatively easy to fit on a 986.