car is a 2004 wrx (40k) and engine light is staying on.

About a month ago i replaced the standard exhaust system with full turbo back decat system that i recieved with the car that the previous owner said he had fitted and had had the car re mapped for and only changed back to original sysem for the sale.

I drove the car for a couple of weeks covering a couple of hundred miles with no engine light showing and running sweet.
About 2 weeks ago i removed my headlights to paint the reflectors. After refitting the lights i went for a drive and within 2 miles my engine light came on and has stayed on since after several starts.

Is this a coincidence or could i have knocked something electrical ?
If it was due to the decat would the engine light of come on sooner and would the ecu be upset by going from no cat, to cat and then back to no cat ??

The car has been running flawlessly with no ill affects at all before and after the decat. The car is going in for a cambelt change and service on the 25th of this month so will get the code read then but was hoping to find out if i have just upset something electrical ??

 

Any ideas ??

 

if the car has been fully decated the light will come on and will need tu be turned off with hand held fault finder which resets the codes shoudnt have any problems with removing headlights

 

The car was apparently remapped for the decat by the pevious owner and only put the standard system back on for the sale. I drove the car for 200 miles after replacing the exhaust before the light came on. If the light is due to decat would it not of come on sooner ??

 

have you checked if there are any codes flash up have you any proof its been remapped he might have bought the exhaust and never had it on

 

seems strange he sold the car with this de-cat exhaust off the car.id have thought if it had had a re-map he'd have been better off leaving it on and giving you the option on taking the o/e exhaust home with you.have you proof of a re-map bud?

 

I thought only earlier models were able to use the flasing light code reading ??

No remap documentation when i purchased the car but has a hks induction kit and bov valve fitted and ticks over and runs perfectly i presumed this wouldnt be the case unless remaped.

When i replaced the exhaust it looked it had been recently changed due to ease of bolt removal and the turbo heat sheild has been cut to accomadate the downpipe.

 

No documented proof of remap. He had put the standard exhaust back on due to been a bit loud for some tastes and also due to having a split in the pipe which i have repaired.

 

The check engine light sometimes takes ages to come on when decated.

Doesnt sound like the mapper swiitched off the CEL code for cat efficiency.

 

double post