I ordered a 2nd stage decat pipe for my blobeye wrx and a first stage decat pipe arrived for the cheaper price of the 2nd decat pipe, thats ok cause i wanted one for the future, but i wanted the 2nd decat so not to have probs with MOT and easier install and things, if i put on the 1st decat will it still pass MOT's?, if u where to change either the 1st cat or 2nd cat what would give u the better output. Also can i run the 1st decat without a remap... aaaand if i was to fit both a 1st decat and 2nd decat what benifits will i get without remap or what probs could i get will i get.

i do have a tactrix cable so i can turn of any CEL lights i get if i run both pipes.

thanks for any input.

 

The first cat is in the downpipe. If you decat this you will fail the mot. However, decatting this will give you the biggest power increase. I suggest you buy a sports cat downpipe which will give you nearly the same amount of power, but will pass the mot. 15-20bhp

The second cat is in the centre pipe connected to the downpipe. You will not fail an mot by decatting this one. Power gains are much less. 5-10bhp

I have a blobeye so there also a pre-cat in my up pipe before the turbo. Not sure about the bug but I think its the same.

 

i just wanted to go with straight decat of the downpipe to save money over buying a sports cat, i dont mind changing them about for MOT's. did u get urs remapped or are u running it without remap like this

 

I haven't done the downpipe yet, this weekend I'm doing both downpipe and up pipe. I will get a remap after this to smooth out the boost and give me more bhp.

 

My my03 wrx is presently 257bhp 275lbs/ft.

H&S Backbox
H&S Decat Centre
Green Panel filter
Samco Intercooler Hoses
Ecutek Remap.

Hopefully, with decat up pipe and prodrive downpipe and remap I should get 280ish.

To get the performance out of the mods you really need a remap. Don't do like I did and get all of your mods on first.

 

My 04 wrx has both cats after the turbo removed and passed its mot without any issues only using the up pipe cat, running 265bhp, and no engine light

 

how will it run then if i do, do the downpipe and 2nd decat, will i get probs running it without a remap, maybe be a month or so before i can afford one.

 

I think you'll be ok for a couple of months. You might get an engine light because of higher exhaust gas temperature due to decat. The problem leaving the up pipe pre-cat in is you are limited to how much boost you can put into the turbo. Safely your not going to get more than the guy above. There is a possiblity the cat will break up and go into the turbo. Before you get the remap done change your up pipe,they're only cheap and you will get alot more power. More like 280bhp after remap. When you get the remap they can switch off the engine management check so you'll never get the light on.

 

Up pipe waiting to be fitted

 

Did you get a remap after d/p centre?

 

why might the up pipe break up if nothing on that side of the turbo has changed?

 

It won't but during a remap they turn up the boost on the turbo. Increasing the pressure to the up upipe because it recirculates the gas through the engine. You will be limited to 260bhp approx. If that ok for you leave the up pipe in. I wished I'd have replaced my up pipe at the same time before remap and got more like 280-290bhp. I got an upipe from the guys here for 65 pounds delivered.

 

It had a prodrive map before i removed the last downpipe cat, as ppp removes one downpipe cat. not had any emission problems so far, 2 years on.
Ecutek when up pipe fitted to 280bhp/300ftlb hopefully

 

I'm hoping for something similar. I have also replaced the intercooler hoses for samco. Simple job. The mappers recon you get more power.

 

I've ditched my intercooler for an STi one and silicon pipes also.

 

Cool should give you even more power. Have you got the sti scoop?

 

Yes mate, and undershield/air splitter
Just got to find time to fit the up pipe now, will it be ok to replace the pipe without an immediate remap? Mapper is on hols soon