HI DO I NEED TO DO ANYTHING WHEN PUTING A DECAT DOWN PIPE ON TO MY 00 IMPREZA. I READ SOMEWERE THAT THE ECU WILL GO INTO SAFE MODE. ANY ADVICE WOULD BE APRECIATED. THANKS DELL

 

no just fit the 02 sensor from the original downpipe into the new one.

Simon

 

Cheers Simon, still learning scoobyne but done a search and found a "hornets nest" of debate. some say needs a remap and others say no so I am more confused now than before I started

 

Ahhh, you never asked if it would need a remap lol.

You may find that it overboosts (use the search for symptoms) when you decat. If so then the only way around it to to map it. Who knows why ppls engines/ecu's behave so differently when they mod their cars. I guess it's impossible to say 'you will need a remap' with something like changing a downpipe. See how it goes and be prepared to either map it or refit the original if you have any problems. Also keep your eye out for any failing MAF symptoms as 99/00 are particularly prone to it.

 

Now bear with me but what is MAF.

 

Mass AirFlow sensor. Basically it measures the amount of air drawn through the induction system and tells the ECU how much fuel to add to give it the correct mixture. If the MAF gives the ecu an incorrect reading then the fuel mixture reaching the pistons is incorrect - Rich isn't great, but lean is really not good at all - esp under boost.

If you experience rough idling or coughs/splutters, hesitation on acceleration etc then it's usually the among the first components to check (plugs, coil pack, maf).

It's not something to get paranoid about, but just to be aware of if you get any of these sort of symtoms. Replacements are easy to get hold of, be be careful if buying from dealers as they want to sell you the sensor and housing - you just need the sensor really.

It's located around where shown here (this is newage, but positioning is the same)

 

Thanks for that as I am sure you have realised i am new to these scoobys but am enjoying every minute of it but NEED MORE POWER