Hi people im new to the subaru life, i have a bug eye wagon with a decat n k+n panel filter n when i get into 4th gear i have a few moments of no power?? Would a remap help?? Didnt know the car had the decat or filter when i bought it.. 

also engine management light comes on but leaves no code. Car is run on super unleaded n pulls fine in every other gear.

any help woud be much appreciated 

If it's not been mapped after de-cat then yes getting it mapped will not only help it's a must. Also if it's a light is coming one because of the de-cat a mapper can set this to stay off.

If you can not find out if it's been mapped or not but it's driving badly a map could be a good idea. I am not sure if there is a way to check if it's already been mapped but most sellers would tell you as it's a good selling point.

I was told it was standard and only bought it as it was very cheap but running poor, this was down to the air box not been tightened at either end and the recirculating valve not been tightened up. After this it was fine bar the 4th gear issue.

was going to ask if i could find a way of knowing if it has been mapped and if it may have had a dump valve or other minor mods took off?? N could be running slightly off. 

Many thanks for the reply though 

It's probably not been mapped and the decat is causing overboost and leaner fuelling (not good ) has it got a boost gauge and if so what does it boost too ?

If it's over 1 bar it's probably been mapped but unfortunately the only real way to tell is to get it plugged in by a tuner . As the common way to map a bug is with ecutek software which doesn't change the physical appearance of the ecu .

Thanks for that, it dosent have a boost gauge so dont know. Should have the funds for a fuel pump and a map just after Christmas so il find out the hard way lol i have minor rust issues to attend to first

I'd suggest to get it on a dyno to check it's running safe , its only about £50 , which is a lot cheaper than a engine rebuild .

Failing that try to keep it off boost especially in 3rd and above when the engines under greater loads

what super unleaded you running it on? needs to be vpower or tesco 99. other supers tend to be 97 or 98 ron. if it was mapped for 99 could be damaging the engine

I live round the corner from a shell garage so its always run on the vpower n on the occasions i dont its tescos super. Many thanks for the input, just trying to narrow down what it could be