1999 Contou SVT performs worse with TruBendz Y-pipe, Help!

I have a 1999 contou svt, with a jimmy rigged ebay cold air intake, res and cat delete, and a newly installed, Trubendz catless Y-pipe....I Put it on today, and here were the results.
Part 1:
I drove it out of the shop and my car sounded great. I was rippin around town and when aroaching 6k and after, while under WOT, it felt like i was making no power and kinda like the engine was low on gas and it sputters..Turns out i Was low and gas so i went and got some, and i thought problem solved!! wrong
part2: Same day about 11pm i went for a drive and decided to do some 0-60 times with my beltronic vecor fx-2. And all i could get was between 8.4-9.0 seconds!!!! My previous runs before the y-pipe were 7.7 and 7.8...What the hell is going on!! I remounted my vector since maybe it is unaccurate? I hope so!, oh!, and when i was doing those runs at night it was still doing that sputter think at around 6K rpm, But just not nearly as bad...Maybe it will slowly go away??? PLEASE HELP ANY SUGESTIONS!!!!!!PLEASE!!!!:banghead:

The y-pipe should not cause a decrease in performance. You've removed a restriction in the exhaust, so unless you've somehow got a bigger restriction in the system, I dont think I would blame it on the y-pipe. You could always unbolt everything from the headers back and see what that does for you.

The y-pipe should not cause a decrease in performance. You've removed a restriction in the exhaust, so unless you've somehow got a bigger restriction in the system, I dont think I would blame it on the y-pipe. You could always unbolt everything from the headers back and see what that does for you.

I have figured out a few things that could be the problem, from cotour.org .let me know what you think.. ps. " i had a 16.73 1/4m run tonight vs. 15.70 before my y pipe. The power flow becomes very uneven between 4500-redline..

more heat from the new y yipe causing heat soak??
Clogged fuel filter?
weak Fuel pump?
Spark plugs?

You mentioned that the engine felt like it wasn't getting gas. Fill up and see if that helps. If so, fuel pump. Could also be the filter. I'm betting the ebay intake, which are well know for being turds, isn't helping. You should feel a sharp increase in power around 4000k when the secondaries open. Do you notice this? You may have a problem with the IMRC, which controls the secondaries. Could also be plugs/wires.

Since you mentioned the engine sputtering at high rpm's, I'm leaning towards the fuel pump. The problem gets worse as there's less gas in the tank, so like I said, try filling it up and see if it gets better. Car's with the returnless fuel system(late 99-00) have a damn near 100% fuel pump failure rate.

You mentioned that the engine felt like it wasn't getting gas. Fill up and see if that helps. If so, fuel pump. Could also be the filter. I'm betting the ebay intake, which are well know for being turds, isn't helping. You should feel a sharp increase in power around 4000k when the secondaries open. Do you notice this? You may have a problem with the IMRC, which controls the secondaries. Could also be plugs/wires.

Since you mentioned the engine sputtering at high rpm's, I'm leaning towards the fuel pump. The problem gets worse as there's less gas in the tank, so like I said, try filling it up and see if it gets better. Car's with the returnless fuel system(late 99-00) have a damn near 100% fuel pump failure rate.

yes the secondaries are opening. I put ten bucks in, cuz im broke and it still seems to be doing it although i did a run last night with next to know gas, and t didnt do it. could it be the combination of my inatke and y-pipe, messing up the sensors or somthing? man this sux.

yes the secondaries are opening. I put ten bucks in, cuz im broke and it still seems to be doing it although i did a run last night with next to know gas, and t didnt do it. could it be the combination of my inatke and y-pipe, messing up the sensors or somthing? man this sux.

Seeing that the problem is intermittent, i too would recommend changing the fuel pump and filter. Both the how-to's are on contour.org.

:grinyes::grinyes::grinyes::rofl::rofl::rofl: good news tonight it hasnt ben doing it because i filled up with gas!!! I hope this is the end of it.. Here is my theory : when i am low on gas, when i launch the car from a dig the gas sloshes back then when i shift it sloshes front, then back again, thus that was the problem i believe!! Thanx guys for all your help!!!!!!!!!!

Aswell, i also had my best run so far....
0-60- 7.5
15.60@ 88.7mph after y-pipe!

vs 7.72
and 15.80@ 87.4...before y-pipe

trubendz really made a difference....awsome...so lets cross our fingers for tommorow. Oh