I currently have a budget Y, sitting in my room for my 99 Cali spec. Everyone now says that budget is making a new Y-pipe for the 99 Cali, that will give better numbers. My question is: is the current stillen Y-pipe ment to get rid of all the cats that the new Budget pipe is going to replace? Will the stillen pipe give better numbers than the budget pipe I have now? Also I have heard that stillen pipes give a bees in a can sound, anyone have a stillen pipe on a 99 Cali?
Thanks,
Dan

I'm Cali spec

 

the stillen y pipe is 2 piece design. if you have a cali spec..(which you have) then you will not use the other piece. The precat stays.

what you can do is get a fed spec exhaust manifold and install it. take the 2nd piece from the stillen y and get 02 sensor holes cut into it.. BAM!!! you are now a fed spec..


this is what i am planning to do. since i have a stillen y

 

Great idea, BUT your going to throw CEL's. A Cali spec monitors the condition of the pre cats. Without pre cats, what do the additional two o2 sensors in cali spec cars monitor?

Remember a Cali spec car has four o2 sensors in the Y pipe. Fed spec has only two.

Thats where the problem arises, and thats why you have to keep one pre cat. The current design of the Cali spec Y pipe fools the ECU by putting both after pre cat o2 sensors on one single pre cat. It fools the ECU into thinking it's looking at both pre cats when it's really only monitoring one on them. So basically your only really freeing up exhaust flow on one bank of cylinders, the rear. Gains are mininal with this design and Budget will tell you that right out, others will just sell you the pipe.

 

i agree on everything. i an not sure if the CEL light will come on though with the precat missing. the o2 sensors will still monitor as before.. hmm

well i guess i will find out this spring and i will let everyone know.

 

CEL will be on for sure. Someone tried the fed spec conversion 3 years ago before there was even a cali-spec Y-pipe out. Only way to get rid of CEL would be O2 emulator or relocate both O2 after the cat if you still have one.

 

would relocating the o2 sensors after a high flow cat still be acceptable?


a 02 emulator would be the best bet.. wonder how much they are?

 

Sooooooo! When is the new Budget Pipe coming out?

 

I believe someone on here has already relocated them downstream after the main system cat with no problems. In that case a fed pipe will work.

If your creative, anything is possible.

 

I'll just add a little more nitrous to compensate for this restriction

 

Budget should come out with a piece for cali spec cars for the people that already have the stillen y-pipe that just replaces the pre-cat. That way you wouldn't have to remove the whole pipe and swap it with the new one, just that pre-cat.

 

I don't get it.

1) On a regular fed spec car, there is an 02 sensor in the precat. The budget y-pipe (for example) just puts the 02 sensors in the pipe where the pre-cats would have been. Don't the 02 sensors just monitor the air? Does it make a difference if it's in a pre-cat or just in the y-pipe.

2) If # 1 is true, wouldn't the same thing happen with a fed spec conversion? If I replace my cali spec with a fed spec manifold, then put a regular y-pipe on (with an 02 hole drilled right where the 02 sensor would've been in the pre-cat),why wouldn't that work. Kind of the same concept of regular y-pipes replacing the pre-cats.

 

I don't get it.

1) On a regular fed spec car, there is an 02 sensor in the precat. The budget y-pipe (for example) just puts the 02 sensors in the pipe where the pre-cats would have been. Don't the 02 sensors just monitor the air? Does it make a difference if it's in a pre-cat or just in the y-pipe.

2) If # 1 is true, wouldn't the same thing happen with a fed spec conversion? If I replace my cali spec with a fed spec manifold, then put a regular y-pipe on (with an 02 hole drilled right where the 02 sensor would've been in the pre-cat),why wouldn't that work. Kind of the same concept of regular y-pipes replacing the pre-cats.

 

I think I got my question answered. I thought that all the 02 sensors looked for the same thing. With that assumption, I figured it didn't matter where they were located. I read some posts on the 5th gen forum. 2 02 sensors look at the airflow. The other 2 look for a drop in emissions. That's why there's the need for relocation after the main cat...so the computer sees a drop in emissions. Search is a beautiful thing