turbojohn

My 997.1 has a consistent 0430 code staying on with turbo at 38000 miles. Porsche tech says sparkplugs leading problem with this 0430 CEL issue in the 38-45K mile range. Anyone out there with 0430 CEL problems (says: 02 sensor or cat defective) as a result of sparkplugs in these turbos in this 38-45K mile range??

TT Surgeon

Yes, it did on mine.

turbojohn

Now tell me, when did you install EP, at the time of the sparkplug replacement? How about with the EP exhaust, have you reached 38K miles on your plugs.....with no code 0430 appearing?
Are you telling me that the P-tech who replaced your sparkplugs did not try and switch 02 sensors to determine if 0430 was 02 sensor or cat or did he ddo the sparkplug replacemet first??

Macster

My info is that if the P0430 or P0420 error code is accompanied by any O2 sensor aging codes to replace the sensors, clear the codes and drive the car and see if the P0420/P0430 codes come back.

If they come back then the converter the error code points to is wearing out, unable in some conditions to store oxygen.

If the P0420/P0430 error codes appear without any aging sensor codes, then the converters are wearing out.

However, a coupe of things. There is an emssions warranty that runs 7 or 8 years and 70 or 80K miles. I forget the exact numbers. Should be in your owners manual, warranty booklet. Converters are covered.

Next, you might buy some time by running a bottle or two of Techron as per directions on the bottle through the car's gas tank to clean the fuel system and remove deposits at the injectors, combustion chamber surfaces and downstream of the engine and this includes exhaust ports, sensors, and even converters.

After the tank with the 2nd bottle is near empty you should change the oil/filter.

What I have found at least with my 02 Boxster and its reoccurring P0430 this helped a bit, enough the car passed smog. That is the error stayed away long enough after I cleared it and the readiness monitors were complete to pass a smog/emissions test.

Since then I have found the error code more likely to appear when I drive the car in colder weather. At least last year during the warm months of the year the check engine light and the error code never reappeared. So far we have not have a spell of warm weather here but it should be here soon.

Also, consider switching to a name brand/top tier gasoline. I have found, at least in my area, the error less likely to appear when I consistently run Shell and Chevron gasolines.

If the spark plugs have alot of miles on them you might consider replacing the plugs. I had plugs changed out that had I can't remember how many miles (a WAG is 60K maybe more miles though) and I noticed no difference in the frequency of the error code appearing after the plugs were changed. But you might have a better result. Up to you if you want to go the plug replacement route.

Sincerely,

Macster.

turbojohn

Great write-up and a lot of useful info. With my turbo, the P-tech never mentioned an 02 sensor-aging code. That would sure alleviate matters and be better than switching 02 sensors from left to right to determine if signal comes up on other side establishing bad sensor if 0430 on opposite side now or bad converter is 0430 stays on same side.
Is this 02 senssor aging code for real??

turbojohn

You report mixed-good stuff . I finally found your aging 02-sensor code. In that search, I see too, Porsche offers free replacement for these same coded-sensors for 2001-2003 boxsters...check factory recall #RC-5467..

Macster

Sorry, but I wasn't being stingy with the error codes: I didn't give the aging O2 sensor error codes because I couldn't remember them.

Besides it is not what I remember they are but what codes are actually read from the vehicle.

It is very important the OBD code reader used for this be sophisticated enough to read *all* active and pending codes.

In some cases there can be quite a few codes. I've seen as many as 6 (P0420/P0430 and the rest misfire codes once in my 02 Boxster when the coils got damp) and the data format of the DTC message allows for up to, IIRC, 64 per Ecu/controller and some vehicles have more than one Ecu/controller that can detect/log and report DTCs. I've seen up to 7 and there can be more than this in some vehicles. (29-bit CAN provides for up to 256 different Ecu/controllers to reside on the bus.)

Be aware too the Turbo engines, at least teh 996 Turbo, uses a wide band sensor at the #1 sensor position. These are interchangeable from side to side but not with the #2 sensor that comes after the converter.

And I believe the aging sensor concern applies to the #2 sensors (the sensors after the converters) since these are used to monitor the performance of the converters.

Sincerely,

Macster.

turbojohn

No such thing on 997.1 turbos as codes for aging 02-sensors. Two top porsche techs thought this a bit amusing when brought up. Said such a thing stands close to searching for pigeon milk.

Macster

Interesting.

I do not have the 997.1 Turbo OBD references, but IIRC the 997.1 uses nearly the same engine as the 911 Turbo (996) and I assumed the OBD error codes and possible faults would be the same.

The 996 Turbo OBD reference has this to say as to the possible causes of a P0430 (or P0420) error code:

Possible fault cause
♦ Oxygen sensor ahead of and after TWC exchanged
♦ Valve lift fault
♦ Aged oxygen sensor after TWC
♦ TWC faulty

But if the 997.1 Turbo engine has an engine controller that no longer bothers to check for any aging O2 sensors, or doesn't consider an aging sensor a possible cause of the fault, then I apologize for posting misleading information.

Added: A check of the 997.1 Carrera DTCs still finds some error codes that reference aging or slow to respond O2 sensors.

I'm curious to know the info is wrong or right so I'll see if I can learn anything more on this from the techs I have some contact with.

Sincerely,

Macster.

turbojohn

I checked with one of these master porsche mechanics. He says for $150 he can hook up the computer inside the 997.1 turbo and drive it around until that 0430 code comes on and tell how good the O2 sensor is, that is how much longer it will be perform its duties. So I stand corrected. However, rather than do that I chose to just install a new one at the cat outlet for $265 . To me it wasn't worth going thru all that pulling off bumper etc, for the $115.

Kevin

Change the plugs, Change the coil packs UPGRADE to the new 997TT coil packs. Change all your O2 sensors and be done with it!

Go over to the 996TT side of the forum and read about the very same issues at 20 to 40K..

Spend the money and be done with it.. It is a minor tune up.