jeffreysurfs

Hi

Recently bought an 02 996 tt...

I took it to local indy for a once over and car checked out well

I am NOT getting a CEL warning at all, and wonder if the fault codes are "significant" enough to warrant a coil/plug service?

Most of the posts im reading on here typicaly have a CEL trigger during operation.

Cheers

Carlo_Carrera

Reset the codes, see if they come back.

Road King

are you experiencing any misfires? When I got those codes, my engine was sputtering/missfiring/breaking up at the top of 4th gear. Problem solved with new plugs and coils.

Macster

If the CEL is dark the codes are stale. These could have arisen from stale gas or bad plugs or a run down battery that might have been replaced before you bought the car.

Best advice I can offer is clear the error codes, even if the CEL is not on. Clearing the codes resets the fuel trims and other things. Then just drive the car. If there is a problem the CEL will come on and you then read the error codes and get the freeze frame data and from this have some idea of what is going and what to do about it.

My recollection is the Turbo has a relatively short plug change interval, around 24K miles. If the engine has any mods this can shorten the plug life and require even more frequent plug changes.

Coils might help. Even though my Turbo was not misfiring I had the coils replaced at around 140K miles along with the plugs -- the plugs had about 10K miles to go before they were due but the tech suggested while he was replacing the coils that would be a good time to do the plugs, too, and I agreed. Afterwards the engine ran better. But it never ran better the several times before when I had replaced just the plugs so I attribute the improvement to the new coils.

Also, before the coils at 132K miles I had all 4 O2 sensors replaced. One was tripping the CEL I forget the error code. The engine felt ok there was no signs of any issues before during or after the CEL came on. I'd start the engine after filling the gas tank, and shortly thereafter -- still at the gas station -- the CEL would come on. I'd read the code, write down the code, freeze frame data, then the clear the code and drive on. Did this several times between Barstow and Livermore. But I had to get the car smogged so I had all 4 O2 sensors replaced. (They were original.) Afterwards the engine ran a bit better. And passed smog with no problems.

My point is even if the misfire errors prove to be stale and the CEL stays off the engine might benefit from new plugs, new coils, even new O2 sensors. The Turbo is just naturally harder on plugs, coils and sensors, and more reliant upon the O2 sensors as the #1 sensors are wide band to allow the engine controller to more precisely fuel the Turbo engine compared to the N/A engines that use narrow band sensors.

jeffreysurfs

No cel's pre or post ppi .the tech said they showed ....i assume when plugged into the diagnostic and read historical data? .car runs smooth, no misfires, clean stable idle, acceleration feels linear.....well linear with a burst of thrust when tt's spool......

current mileage 97k ....records show coil/plugs done at 60k.....the records are solid up to about 85k and then no specific shop paperwork altho the carfax showed a service at about 90k....alas no paperwork to verify what was done

plug interval on 996tt is 30k

no mods

and the car does have a fresh battery....installed by dealer pre purchase

and thank you Macster.....im an aspiring wrencher have basic auto repair knowledge ....and want to do the plug/coil/o2 work myself. i have deep diven the tech articles and steps to access the coils/plugs.....a whole bunch of not too hard to remove pieces.......more about keeping it all organized

"02996ttx50

you are well overdue to replace the plugs. given they are connected to the coils. you can inspect them for cracks. 997 coils are fairly robust. i think i've swapped them twice in 7 years.

i change plugs approx every 10k miles. i have learned over the last decade. plugs are cheap. 50 bucks and a cpl hours to r&r. max. tuned cars eat plugs. you said you're stock? they eat the them more slowly, and you are still "overdue". GL

jeffreysurfs

i have the tools

Read step by step by step....on renn tech..and pictures that help identify locations..seems like the inter coolers lift out a certain way........some finesse moves you figure out after doing it.first time.... and consciously placing the unique screws,and other connecting hardware separated/organized...and its just like any car ...the heat shields on turbo have a trick.......once you get access to engine block ...coils come off fairly easily....and with i imagine an extended spark plug rod socket ....

i will gather info on o2 fix as well.

i bought a good condition exterior..seal grey..has a few rhis and thats...great interior cept the interior grey plastics show black....i dont eve see them..god seats in all 996's.. and im driving 3-5 drive days a week marin to south sf.....and back country sonoma...amazingly docile around town if not stomping....surprising light clutch hydraulics...remind me of a 98 saab 900se......cept the saab had no feel and the pp6tt...although a little off weight balance of clutch to accel...im smoothing it out enough..

rebuilt g50 at 85k 1 ans 2 gears and synch including clutch slave and accu,

alternator in last 10k miles..

rear fin operational

$38,500 ...

"02996ttx50

very cool you got a car with a refreshed g50. that saved you some coin. 85k is about when my bearings went.

lol @ S SF. that city that burns clutches.. GL with it.