High Flow Cat or test pipe??

[cashmoney]

My 00 celi is throwing a catylist code...im trying to decide what to get to replace the stock converter give me ideas

[Seven Of Nine]

Go decat "test pipe" if you get a CEL do the MIL Eliminator mod. Cats are restrictive., but might be a good idea to go for a flanged design have you old cat welded with flanges also so you can swap back for emmissions.

[cashmoney]

Hey could you explain the whole CEL and MIL thing you are talking about? not sure i understand...but ya i do want to go with a test pipe and do you know where i can find a good one?

[Seven Of Nine]

Your best bet is to contact local exhaust or body shop have them make you one up shouldn't cost alot over there but use SS rather than mild steel as it will last longer.
The the CEL basically when you do a decat you have 2 exhaust probes primary and 2ndary the 2ndary will cause your Check Engine Light CEL to come on as you are taking out the cat thus the readings will be wrong on the 2ndary. But if you do the MIL Eliminator it fools the ECU into believing the same figures voltages are being produced.

How to build the MIL go here NewCelica.org Forum - Catalytic Bypass (how to make MIL Eliminator)

Also if you wanted to could have a small 90 degee L pipe welded on and relocate the 2ndary sensor so that its parallel to the main exhaust pipe facing towards the engine kinda mechanical MIL no need for cutting / splicing wires etc.

[Wiseco]

A cat offers something like 0.3 psi of restriction. Unless you're boosting, a normal cat or no cat will not make a difference besides fucking our ozone.

Keep your cat on, If its garbage, thats because you killed it, a cat dosen't die, you have to kill it. (running too rich or lean, rust, dents).

High flow cats are a gimmick for the better part of them. Its just smaller and less efficient.

You're getting a code, thats either a cat faliure (means there's another problem somewhere) or an oxygen sensor problem.

[MartinGouda]

keep it legal... runa high flow and a nice o2 sensor... it will pay off at the pump

[cashmoney]

well i plan on eventually getting turbo so thats why i wanted a straight pipe...the reason my cat is fucked is because my MAF sensor was fucked up...just replaced...which caused the catylitic code. I understand how shit works...just wondering what others think about the straight pipe. If i got a high flow would i need to get a diff sensor or modify??