I have some modification on my car, something like intake, uppipe, downpipe
catback to muffer, can I run the car as stock computer setup? or I better
replace it to some after UTEC?

 

What you describe is a full aftermarket turboback exhaust system and is not recommended to run without aftermarket engine management or tuning. The TXS UTEC you mention is usable but it has fallen from favor in the past year as more convenient tuning tools have become available, the most popular of which is the Cobb AccessPORT.

Ready-made tuning maps are available from Cobb or your car can be custom dyno-tuned from your local shop using your AccessPORT to store custom maps.

Please always state what year and model car you drive when posting a question. You didn't fill out the Car field in your member Profile.

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0==WW==0
"…axles of evil…" - george w. bush

 

ok, thanks for remind me that. I was just trying to describe all the part
aftermarket turbo back exhaust system is way more easy to say.
my car is 2002 wrx, I should fill out more information on my profile~~
so without those custom map setup. is my car just run poorly in stock map?
i use all HKS exhaust system.

 

Your car will run but will not be at the ideal tuning for things like ignition advance, boost, and air/fuel ratio, especially under full-throttle. Engine management allows maximum safe power.

The factory ECU can only compensate for a very small range of change, not the complete exhaust system replacement that you have done.

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0==WW==0
"…axles of evil…" - george w. bush