I'm about to install my y-pipe and a test pipe, I was wondering if any of you got any codes (SES light) after replacing your cat with a straight pipe and what are those codes (i'd suspect they're related to cats, eh? ).

 

well, I'm sorry to give false feedback, but i'm looking to do the same with my cali spec y2k, where did you get the test pipe, and where goes the o2 sensors? if you don't have those in place or (so i've heard) the difference will not be measured and will throw a code

 

Naw you shouldnt get any code, I didnt. The o2 sensor is upstream of the cat so it shouldnt be a problem.

 

I gotta check where the o2 sensors go in

 

The O2 sensors go into the Y-pipe in each Y split... the rear bank should be no different from stock as far as readings, because I think the rear precat is in the rear manifold?
The front O2 sensor, on the other hand, will notice decreased catalyst efficiency because the Y-pipe removes the front precat.

However, the test pipe shouldn't make a difference. I believe, O2 sensor-wise, this setup is no different from any other Y-pipe install on cali-spec 2000's. There is no O2 sensor behind the main cat to test its efficiency, both downstream O2 sensors test precat efficiency. (as a side note, a 2K with SES light issues with a Y-pipe could probably have an O2 sensor bung installed in the B-pipe and the front O2 sensor relocated back there, so it WOULD become a main cat efficiency tester, which should reduce the SES light incidents... but that wouldn't work here, because you're removing the cat too.)

To recap: There are 4 O2 sensors present. The two upstream sensors (one in each bank) test the exhaust gas for air/fuel ratio purposes, and the ECU reacts directly on these for dynamic Short Term Fuel Trim readings. The downstream O2 sensors (one in each bank), as far as I know, are only used to test efficiency of the pre-catalysts. I think someone mentioned they might be used for something else, but I'm not sure.

 

Just don't get a CustomMaxima resonated test pipe as they crack, I fixed mine one time and then said fuq dat and got me a new test pipe from Warpspeed. No CEL lights on my 01 Cali spec. Then again I don't have no cats at all and my rear 02 sensors just lay there on the tranny secured. www.02simlulator.com takes care of my "cats"

 

fixed link-- http://www.o2simulator.com/

What is this, a PIC or 555 Timer just sending a pulse? Neat idea.

 

thanks guys.

i already got my test pipe and it's from warpspeed. good to know

 

its a little chip that takes the refference voltage, reduces it to around .6V and sends it on and off to the ECU. For anyone trying to use this on a 3.5L or Cali spec 3.0L when doing headers, I recomend you get the dual version- as you will be removing 2 cats while doing this and it WILL set off a check engine light for catalitic converter efficiency below threshold.

 

Nice. Sounds like a simple circuit too (just a 555 timer would do that, I think... switching output of a zener diode or voltage regulator)

 

does the test pipe really make a difference??i am going to replace my stock cat. wanted to look into options.

 

i believe carabuser is going the boosted route, so it should help more there than compared to NA.

as long as you don't have headers which require you to relocate the rear o2's into the b-pipe region, you'll be fine. But the o2 simulator route is the easiest fix.

 

A test pipe definitely makes a noticeable difference. The exhaust flow is not slowed down as much with the test pipe resulting in better free flow of the exhaust gases and more power. Only thing you have to worry about with not running a cat is emissions...

 

I have the Stillen Y and a CM test pipe, they've been on for a couple of months, so far no codes, and I don't expect any, unless you have another problem elsewhere. I haven't had any problems with the test pipe, except initially getting it to seal against the Greddy, but now it's fine. I wouldn't expect to pass emissions either, perhaps you might on a warm day, after you've put a few miles on the car before you test it.

 

mixed reviews here. some say CM is good, stillin and Warpspeed have also been talked about. what is the price difference??

 

So for just a Y-pipe on a '00, a dual version would be overkill?