Hi

I have uk2000 turbo classic with a few modifications, (PPP upgrade, decat exhaust nur spec, larger TMIC, apexi air filter). Very intermittently my CHECK ENGINE warning light comes on and then goes out approx after 20-30seconds. Roughly happens about 2-3 times on a 15 minute journey and there is no real pattern to it. Doesn't seem to do it at high revs or high boosts. Seems to come on when at idle or low revs/low speed. Does occasionally come on straight away after start up of the engine. I have checked the manual and it states that the warning light basically means a problem with the cars control system. Any ideas why this is happening?? Is it a knock sensor (I would have thought this would be triggered at high revs/ high boost). BTW my car is running a 1 bar and the car runs very well.

Any thoughts

 

Have you read faults off the ecu? It could be a huge number of things a diagnostic will read the fault code its left.

 

What's the cheapest way to do this? i.e fault code reader?

 

I do believe the classic has its own built it diagnostics but somebody will confirm this.

 

http://www.subaru-impreza.org/forum/...c-impreza.html

There you go.

 

On mine these symptoms was the lambda failing.

 

Here are a list of the codes for you.
http://www.scoobypedia.co.uk/index.p...odeDefinitions

I was getting the same intermittent CEL at low revs and idle,it was a faulty knock sensor.

You say it has PPP has this map been put on the ECU or have the parts just been bolted on without a remap?

 

Car had PPP ECU remap after 500 miles from new. I have added nur-spec decat exhaust, apexi high flow air filter and larger volume TMIC. Boost is at 1 bar. Is it possibly these mods upsetting the system?

 

Possibly.
you have changed air flow in and out without a remap which is never a good thing,you won't be benefiting from those mods without a remap.

Is it just a panel filter upgrade or a full induction/cone filter? Mafs are sensitive to induction kits.
Have you read the fault codes yet? only takes 5 mins and will tell you more about your CEL.

 

I have just run diagnostic using the black wires and have got code 22 and code 23 come up, "knock sensor" and "mass air flow sensor circuit".

Should I fear the worse as engine light is still coming on from time to time.
Obviously I don't know which of the codes is re-occuring the most.

What is the best way to proceed with this??

 

Don't fear the worst just take it easy until you sort out the problem.
Have you done an ECU reset using the black and green plugs?
I would start with this,then if the CEL comes back on do another error check to see what code it throws. Mine was throwing the knock sensor code and turned out it was a faulty knock sensor,new one fitted and it's all good now.

Apart from needing an engine rebuild,,,possibly
Ps that's just mine and not what I'm saying yours might need lol

 

How do I do an ECU reset?

 

Follow these instructions,if you have not done the reset then the error codes will be stored so previous errors will show up even if you have sorted the problems.

http://www.scoobypedia.co.uk/index.p.../ECUReset#toc3

 

Thanks. Some people reckon you can reset the ecu fault codes by leaving battery disconnected. I have tried this but when I turn ignition I get a beep and the check engine light stays on until I start the engine. I presume this hasn't worked and I need to carry out ecu reset as instructions above?

 

As far as I know,just unplugging the battery won't clear the old stored error codes,the proper reset procedure will.

Btw the CEL does stay on with ign until you start the car,this is normal

 

Time for a new maf sensor. I used to replace mine every 4 years.

 

Should I get a beep noise when I turn the ignition. This maybe my immobiliser fitted to the car beeping

 

Possibly immobiliser.
Is it just a beep or constant beep?
Does it do it with the doors closed? Mine has a key left in ignition warning(beep) but only when the door is open.

 

No its just a beep then the car starts. I guess the best way to check if I have cleared the faults is to run another diagnostic test (black to black connectors) and see if same faults come up

 

If you have done the reset correctly

 

Has it been mapped for the changes, when, and by who?

 

#post 8

 

Hi mate, as I was changing the spark plugs last night I disconnected the battery completely and touched the positive/negative terminals together and the fault codes have been cleared. I have checked the faults again using the black connectors and nothing is stored, CEL just continously flashes now.

So far no CEL light on a 20 miles drive tonight, fingers crossed