Steve's MLC

Or does it? Did you even check codes? Listen to the veterans.

uswrnk54

Will have to invest in a scanner... Any recommendations?

Ahsai

Depends on price range
$20 mini obdII Bluetooth + the "Torque" app (you need an android phone though). Real-time data, reads and resets codes.
$50 actron, no real-time data
$75 innova 3040 real-time data
$290 durametric, Porsch specific and most powerful including airbag reset, cam deviation reading, etc.

You would need real-time data to diagnose any further than just reading the codes.

ghostofpain

Hi guys,
picking up this post. My car had a flashing cell too the other day. I was riding hard on the autobahn and while going for top speed at about 310 km/h the check engine flashed. No weird sound, smoke nothing. I decelerated and after about like 15 endless seconds the light were gone. I checked codes....nada. My mech said the lambda probes wont last forever. So i guess in my case one probe is getting old.
My car (996 turbo) got 200 cell cats and tune

ghostofpain

Misfire will lead to codes btw.

JayG

I had a flashing CEL for a very short time and the display said to drive slowly to service location
In my case, it was a temporary misfire

m3driver

Flashing CEL even on US cars and trucks is emissions related that can damage your cats. It does not just mean mis-fire.

Schnell Gelb

A potential CEF /MOF thread nixed by sheer good fortune :-).

Macster

If one O2 sensor getting old they all are getting old. Replace in sets. The ones in my 2003 Turbo lasted around 130K miles. Some get more miles, but most get fewer miles out of these.

The Turbo uses wide band sensors for more precise fuel control so these want to be operating in top form to ensure the more precise fueling actually happens.

Plugs too don't last for long in these Turbo engines. Be sure the plugs are not past their change by miles or date. At the same time check the coils. There are some who believe the coils should be replaced on a regular or semi-regular basis, and this applies also to the MAF. I've always been a don't fix it if it ain't broke type but a Turbo is hard on its coils. The turbo heat plays a role I think.

The MAF runs hotter and because the Turbo makes so much HP which requires a lot of air the MAF is working harder than it would on a NA 3.6 engine. As a result the MAF can have a shorter life span.

Also, a tune makes more demands on the engine and its subsystems and can bring out a weakness that the stock tune didn't.

ejdoherty911

I really don't know how you go from flashing CEL (which is not good) to everything is perfect, without ever reading the codes or having any knowledge what caused the flashing cel. Keep on truckin' I guess.

DTMiller

Yeah, at least throw a code reader on it.

Macster

Flashing CEL is a rich misfire. If the CEL goes dark the misfire condition is gone and there will be no active error codes stored. There might be permanent ones -- that is errors that can only be erased by the DME after it has counted enough warm up cycles with the error condition absent -- and there might be pending codes.

Rusty Heap

It seemed very ironic, but while driving my 03 C4S to my indy shop for some other repairs, how opportunistic that it threw a Blinking CEL and said to drive directly to dealer for diagnostic.

their Porsche OBDII reader showed RH cat had thrown a code. they reset all error codes and 600 miles later including a track day, no more codes or issues.

bernardbarbour

The last time I had those symptoms, here's what I found. Just saying

Macster

It is very important to get the codes, all of them. Active, pending, and any permanent codes. Get the freeze frame error code and data too.