ok..i have stillen intake and y-pipe but no cat-back.
after adding y-pipe, my car would just stall when i come to a stop...
this only happens when my engine reaches normal temp and right after i accelerate hard then stop...
does this have to do with my stock exhaust being smaller than the y-pipe in diameter?
anyone else had the same problem?

 

You can look at my setup in my sig... I never ran into anything like that while driving, but have ran into problems starting the car after the y pipe was installed.

Sometimes it would crank for a few seconds before it starts. Weird...

 

HMMM makes me rethink my Ypipe addition before my warranty gets close. Have you taken it to the dealer yet?

 

...the fact that you all have CA/NLEV emissions? Remember that with the Y-pipe you still have one pre-cat on the car (the front one). The O2 sensors (the front and rear ones) might be reporting to the ECU different readings of exhaust gas mixtures. I'm definitely not an expert on these things but thought I'd throw that one out there for consideration. Could it also be vapor lock?

I, too, have CA/NLEV emissions and a Y-pipe. What I experience is the following:
1) Kev's problem. This happens very infrequently.
2) Most times, when stopping at lights I press in the clutch as I approach the lights (at about 5-10 mph). The rev counter drops from 1500 rpm to about 300 rpm (with the clutch pressed) and the car feels like it's going to shut off then it quickly raises back to 650 rpm.

#2 above sounds like the problem you guys are having but your's actually shuts off.

Peace....

[Edited by 2K2DEMAX on 02-09-2001 at 10:31 AM]

 

I have the fed. spec. with a cattman y and have never experienced that kind of a problem. 2k2demax may have a point there.

 

#2 on your reply is exactly the kind of problem i'm having right now. but, occasionally, engine shuts off. the engine does not shut off when i'm driving, only when i'm slowing down to come to a stop with my clutch depressed. it can't be my O2 sensors because if my O2 sensors were reading different readings, then my check-engine light will come on.(which hasn't happened)...
i was hoping that after i put on a B-pipe, this problem would be sold. the reason behind this assumption was that since my Y-pipe is 2.5 inches in diameter, and the rest of my pipe is only 1.5, i figured it's bottle-necking like crazy at the cat and there's just too much back-pressure surge...which is a very not very machanically inclined opinion of mine...but...hmmmm...
i never had trouble while i start the car..the car starts just fine...it's just these annoying problems and people thinking that i don't know how to drive stick shift!(they're like...'ahaha..he just stalled on his manual...')

 

Hmmm, come to think about it, i've been having the second problem ever since I got my oil changed at 16,000 miles. BUT all I have on my car is the Stillen intake. So I'm not certaint that it is the Ypipe's fault.

Anyone else with just an intake have the problem of rpms dropping to point of sputtering after coming to a stop. It tends to do it more when I've been driving it hard though

 

the dealer? no way man....on the stillen y-pipe, there's a steel plate welded on to the y-pipe which reads 'not street legal and offroad use only'...
if they see the y-pipe when i bring my car to the dealer for the exhaust problem, my warranty is toast...

 

My thought process behind my assertion was that because the rear O2 sensor is recording different readings (rich, lean, etc.) than the front one because of the absence of the cat on the rear one, the result would be that the ECU might be cutting the gas too soon. The reason why the engine light hasn't come on is because it's probably still within the acceptable limits. Remember, it's the front pre-cat that causes the ECU to go bonkers and if rthat one is in place then it won't complain.

On the B-Pipe thing, I have a custom one 2.5" in dia so I don't think getting bigger catback piping would help.

I've been thinking about the remaining pre-cat for some time now so that's why that's the first thing I thought of. I'm thinking of a way to have it removed without causing the ECU to go "ape sh*t". My initial thinking is to relocate the O2 sensor in the front pre-cat to the just behind the main cat, just like the fed emissions model. This might "trick" the ECU into believing that everything is fine. If this happens then ...goodbye front precat and helllloooo more HP. Pardon my rambling...just had to get it out of my system.

Peace....

 

just went to the dealer on wed withe my y-pipe, intake, high flow cat from RT, and crankshaft pulley....... they didnt say a thing..... the only thing that voids your warrenty out of what i have is the high flow cat unless you make the excuse that you went over a speed breaker and craushed the stock one and had to replace it...... the other thing is a level 10 torque converter if you have an auto and the super charger of coarse... maybe a few other but not sure..... so you shouldnt have to worry about it... my y-pipe doesnt do what you guys are talkin about is it happening to veryone with a 5-speed or is there anyone with an auto doing this too???

 

First let me preface by saying I am not a Nissan mechanic. I have been reading and listening alot lately as Dallas and I get ready to prototype the 5th Gen y-pipe. One theory about having the front precat on and the rear removed is that each cylinder bank may run at a different temp. This (I believe) is what happened to my 93 SE with the Cattman pipe. I had a BIG dent! The car ran ok, at least I thought it did. When we were getting ready to dyno our WSP y-pipe to compare it against the Cattman pipe, we pulled out several of the plugs on the front bank of cylinders. They looked very good. We went ahead with the dyno. I had a high speed miss and not as much h/p with either pipe as I felt I should have. When I got home, I had the local Nissan dealer check into it and he found that my rear three plugs were nearly burnt up. Thank God for plantinum plugs. His theory was that because of the big dent, the front bank of cylinders was runnig rich. The single o2 senser(located by the Cat) read this and leaned down the combined exhaust gases. Causing the front bank to run ok, but doing so leaned down the rear bank enough to burn up the plugs and damn near my engine. My words of wisdom when moving around o2 sensers would be to do moniter the temp. of each cylinder bank closely. There is a reason Nissan went to o2 sensers on both down pipes. Its possible I may be off base here and if some one can explain to me how my problem occured, I will take it into account.I can promise you that when we do the 5th gen y-pipe we will be monitering both banks closely. Thanks Dan WSP

 

I don't know why you guys are haveing soo meny problems after adding mods to your car. Check engine lights and car shutting off and stuff. I added the stillen intake without using the front O2 sensor, No Problem. its hanging in the wind right now. No check engine light.

Then I add my Y-Pipe cattman SS. no problems. the cars tone has changed but NO Check Engine Lights or the car shutting off. the only thing thats changed is that I notice the car gives me less gas milage but I know I drive the thing like its my last day on the road. Red lineing and just Brutal on it. still get about 350 or so miles out of a tank vs 400-450. I sometimes feel bad for my car. I drive it rougher then anything I've had b4 and it still comes through for me. I use to have a camry a few years ago, I bet If I drove that think LIke I drive this car, that thing would be in the ground by now. Ok geting off subject here. My advise. take a look at the o2 sensors that are in the factory Y-pipe. the one in the rear is real easy to break so make sure the wires are not broken off.

As far as the dealer goes. My dealer don't care. the guys there actually like the way my car sounds. and it doesn't sound too bad. .just a little growl at idle and low Rpms 1500-2500