Check engine light (solid) - DIY or not...

Got my 996 a few months ago - was a lovely '98 with only 30k on the clock, just had a major service with no issues. It's been relatively fine (though I've only covered about 1500miles on it so far) - however, from the start the idle was a bit lumpy and on ignition there was quite a strong smell of petrol (running rich I assume). Was out last night and it started getting very stuttery on accelerating then the check engine light came on (solid, not flashing). I'd had the PPI done which showed no major issues (I think he said there was a small split on one of the silencers). I should also mention the coolant level indicator had come on a couple of weeks before but there hasn't been any overheating. A bit of reading suggests quite possibly the MAF sensor or a pencil coil - things are very tight atm as I have a baby coming in 5 weeks and a lot is being spent getting our house in order, so I'm considering DIY. I'm pretty handy (done various work on bikes and previsou cars) so I'm considering getting a code reader, however, some posts mention the earlier 996 might not be obdII compatible, could anyone clarify? On the other hand, I'm a bit worried it could be something more sinister (the engine sounded slightly different on startup, a kind of high pitched whir). There's a local indie I was considering taking it to but I'm a bit mistrusting of garages going from past experience - is it poor form to get a garage to do a diagnostic and do the fix myself if easy enough (letting them tackle more tricky stuff if not)?

Just wondering if anyone had any thoughts - reluctant to use the car until I get this sorted!

Well apart from the engine sounding different the other symptoms do sound like either MAF or coil packs in any given amount. First thing to do is to get the fault codes read and interpreted correctly. Any good indie will be able to do this for you for a small cost (they will also listen to your engine sound) You will them know what the problem is and can decide how you want to approach it to best suit you. good luck...we've all been there!

Thanks Mathamb, I suppose it is the best scenario, I just didn't want to mess anyone about so had thought about buying a code reader.

You have to be a bit careful choosing a code reader for a '98 996. The DME (engine ECU) on early RoW 996's isn't truly OBD2 compliant, and hence a true OBD2 code reader/scanner may not read all fault codes and pending fault codes. USA cars were truly OBD2 compliant, so not an issue there. Maybe someone here can recommend one that works. If you are anywhere near me I'd be happy to plug my Porsche tester in for you.

Hi Richard, Yeah, thanks for the info, it was actually a previous post of yours I'd read with this info, hence why I didn't want to rush out to buy a reader. Unfortunately you're at the other end of the country but thanks for the offer :thumb:

Where abouts are you? I am Worcestershire if any closer... happy to help also. :thumb: Lloyd

Afraid not Lloyd, in Glasgow! But thanks also :thumb:

Quick update, have done quite a bit of reading on the MAF and trying to find the code reader situation on a '98 (though I couldn't get to the bottom of that). So, I decided to just try cleaning the MAF sensor and did and ECU reset to clear the CEL - just had it out for a 5 minute spin but it seems immediately better, no 'hunting' for power and the CEL stayed off. The idling is still a little lumpy but definitely less so - hopefully it will get better with the ECU ignition adaption over the next week and fingers crossed the CEL doesn't reappear. I'm just wondering if my short low-rev journies have been contributing...though the idle was lumpy when I got it.

Chriggy it would be no problem getting the codes read and having an experienced indie listen to your engine, and you could then decide whether to do some jobs yourself, but at least you get the option this way. I am sure that all will be fine, good luck with the baby and may I say this particular thread shows what makes this forum simply the best! Mike

Thanks Mike - had it out for longer this evening and all seems well, idle is a lot smoother than before, still no hunting and CEL stayed off. Was getting worried we might need a taxi to get the maternity ward there! :hand:

Hi Chriggy, Had exactly the same problems myself, and then some! Turned out to be a combination of faults. Started by replacing the ignition coils, which can be bought from GSF carparts for about £140 for all six. While you're in there, check the spark plugs are torqued properly, as I had a chirping noise following a service, which turned out to be one plug not being tight enough. Next I had it diagnosed properly, and had the MAF sensor replaced. These are about £150 - £160, and while cleaning can help for a bit (I did try with electronic solvent cleaner before replacing), others told me that it would only last so long after this. Was like a new car after this, but still very rough at idle, with the check light coming back on now and then. The diagnosis said that there was an oxygen sensor 'flatlining' on bank 2 exhaust. Replaced this myself yesterday (£100 through Porscheparts), light has cleared itself already, and my baby is pulling like a train. Was a headache changing the sensor mind - old one threaded itself while unscrewing and was stuck in the exhaust, so had to remove both exhaust cat' sections, and take the one with the knackered thread to a local garage to get tapped out, as the size is an 18mm metric fine thread, and pretty rare. Hope your problems aren't so deep, but could help others :thumbs:

Thanks for info of your experience pokrok, may help down the line! Just had it on a 7 hour round trip up north yesterday/today and thankfully it hasn't skipped a beat so far, we'll see how that pans out though!