Check Engine After Hard Driving.
 

Just got my Terzo edition. Took it for a test drive and everything and drove really well. Once i brought it home next day warmed engine up for about 10mins then took it for a hard drive and my (Check Engine) light came on. It wasnt like i was red lining it or anything but it went off and sometimes after some hard driving it comes on but goes off again when it feels like it. Also today it juddered but it only happened once then picked up speed and was ok. I would check the code but can only do it when its on. It has a air filter and i dont think it would have been tuned on ECU could this be the reason why im gettin this Check Engine light? Just for your reference im using 99 octane tesco. Should i use V Power??

Thanks

Smurf

Smurf,

The fault codes from the CEL are stored in the ECU and can be "read" at any time.

Follow this proceedure and it will report back a code which should let you know the reason for the CEL

Scoobypedia | Trusted knowledge for everything Subaru | Knowledge / Reading ECU Fault Codes

Jason

Hi Smurf,

See you are making your first trip into the help pages already.

jsh1 is right, fault codes are stored. Read them off and get back to us. Don't worry too much, most fault codes are easily rectified. Just remember to reset the ecu after you have taken the necessary action so you don't get confused if a new fault arises.

Ok i connected the black lead and got the flashing check engine light. But i cant seem to work out what it is? Ive got a video that ive uploaded. Check it out here YouTube - Check Engine On Impreza

Thanks

Looks like code 23 Mass Air Flow Sensor Circuit

Is a Terzo a 99 model? If so, the MAF is pretty weak on those, and fitting an induction kit tends to make them worse.

Thanks mate ur a star. Thanks for the quick response. Car has a filter i dont belive it has been re-mapped so think that could be the fault. I may just put a standard filter and put new Mass Air Flow Sensor.

My Terzo is 98 so should i get a MAF from a newer impreza? The check engine dont come on only when i boot it it comes on. U replied just as i posted i thought its the induction filter.

Thanks

Just looking at that video. I think there is 2 faults i think the first one is 22 - Knock Sensor and there is also 23 - Maf Sensor. Am i right??

That's what it looks like

22 Knock Sensor
23 Mass Air Flow Sensor Circuit

100% certain the above is what it looks like it's flashing back.

Yeah does look like 22 and 23 now I look back.
Go for a an ecu reset. I used to get the knock sensor light and it went after clearing it.

Ok the guy i brought the car from had a spare Knock Sensor and he got that from the last owner he said so it may have been changed and the code not cleared on ECU. Like joey_turbo said ive cleared the ECU and im now getting the ok code. Fingers crossed it will be sorted now. Are all the Maf sensor's the same on classic? Is there any particular one i should buy? Im guessing there are different ones?

Thanks

Terzo is a MY98 (launched April 1998)... So it's the orange label 'robust' 90mm (OD of housing tube) MAF... Or you can upgrade to a straight swap-over Q45's MAF (same size) but connector would need rewiring (piece of piss)... plus the MAF would need recscaling via a remap...

The great thing about the Q45 route is that you'd be future proofed for further mods/remaps upto 460+ bhp (or of course fit the OEM STi MY97/98 orange label MAF for up to a similar figure).

Good, used Q45's go really cheap on eBbay though - as low as c.£40 if you're lucky!