EsQueue

iTrader: (2)

Hello, I've already decided to purchase a y pipe for my Cali Spec 99 i30. I've been doing lots of research and want everyone's opinion.

My options are either getting a Cali Spec y pipe that keeps the front pre-cat. With this option I will add a second o2 sensor near the front pre cat so avoid a CEL. The problem is wouldn't the uneven pressure damage the engine or cause future issues?

My other option is to get a fed spec y pipe and replace the front intake manifold with that of a fed spec. I then will have to either extend the wires of both of my "after pre-cat" o2 sensors and relocate the sensors after the main cat to avoid a code or get a dual output o2 sim.


What do you guys recommend. I've seen a dyno posted by a member and it seems that the gains of the fed over cali spec y pipe are very minimal.

EDIT: I forgot the main reason why I wanted to switch. It was so that the Wideband that I will install don't get false readings from the pre-cats.

cartman854

iTrader: (2)

power wise they are almost the same, so, do what is eaisiest for you to do.

EsQueue

iTrader: (2)

What do you plan on doing about your rear lower o2 sensor?

Snypa

iTrader: (35)

I think this might be my next mod as well. Let me know how it goes and what route you take.I hate Cels as well.

EsQueue

iTrader: (2)

Made up my mind. I will install some extra 02 bungs in the fed spec y pipe and use the spark plug antifouler trick to stop the code.

Snypa

iTrader: (35)

Where are you finding these things? Is there a stickie around here?

Quickywd01

iTrader: (16)

I had my cali spec wsp y-pipe installed a few months ago. No cel's. To address the front pre-cat I will replace the exhaust manifold with a fed. spec manifold. Only because I saw what happens to pre-cat's on F.I. applications. If your car is stock just install the y-pipe and don't worry about it. If you continue increasing power (and I don't mean a cold air intake) then you should look into what I mentioned.

maximariceboi

iTrader: (32)

The 99's are really restricted with exhaust flow due to the pre cats. you would actually free up more power if you changed the fed spec front exhaust manifold and and get the fed spec ypipe. It's a bigger job though.

EsQueue

iTrader: (2)

I am installing a supercharger. I've already purchased the Fed-spec WSP y-pipe. I will purchase a Fed-spec front (left) exhaust manifold so that everything bolts up. I will also add 3 o2 sensor bungs. 2 for the after-cats with the antifouler trick to avoid cel and 1 after the flex pipe for a wideband that I am installing.