Welcome to RennTech.org Community, Guest
To all 996 owners with PSE, especially those with a 4S.
I think my 996 C4S exhaust behaves oddly. I think it's a fault but you might tell me it's normal behaviour. The problem is that I've always had this 'fault' on my car so I don't know if it's a fault or intentional behaviour. If you have the same car, perhaps you can shed some light on this.
When I start it, it's noisy and sounds great. It quiets down as it runs for the first 5 mins.
I have the PSE system and when I press the button you can audibly hear the exhaust note change - quieter when on and louder when off. Default is off so loud.
Here's the rub. Up to around 1500rpm it's got a good noise then it fades out to the point where it's so quiet it's like driving my partners Yaris. If I keep accelerating, when I get to around 3500rpm the exhaust suddenly gets loud again. I mean it's immediate - like someones flipping a switched marked loud. It sounds great.
It happens in 2nd and 3rd gears most noticeably and the PSE is in the 'off' position. If I have the PSE button on, then it's just quiet all the time and that works fine.
So why the silent spot?
I did read somewhere that German market cars might have had a system that turns on and off the PSE at certain speeds to prevent people driving round residential streets with a loud exhaust but information is thin and I don't think I was ever on UK cars.
I have also had a small go at checking vacuum pressure at idle on both sides of the Y piece in the engine bay but both hold good pressure. One side has only a microscopic leak but not enough to cause this kind of issue.
This will be my first post, thanks for a great forum !
I've recently purchased a exhaust system from Design911 in the UK which has the valvetronic function on. This is said to replicate the PSE which my car does not have factory installed.
Wired it up and put the vacuum hoses, tested the system and it works fine.
Over to the issue for my car:
When starting up the car, the neutral positon of the valves is open, which means a lot of noice from the exhaust.
When switching this by the solenoid, sending vacuum into the system and the valves closes. This means less sound.
But when the valves is closed the car wont run properly at the RPM range of 5500-7000 RPM's there is also fault codes for misfire on cylinder 2.
The strange thing is that this works perfectly when the valves is open. I've tried two differnet vacuum sources, into the ressonator and also for the left hand side cooling system vacuum solenoids. Without any differnce. I tried to run vacuum directly to the vacuum actuators on the exhaust without any difference and also tried manually applying vacuum and using a one way check valve to keep the vacuum while not connected to the cars vacuum line. No vacuum leaks, no fault codes when driving with the valves open.
Same result every time. So have anyone had some similar issues to their car ?
Thanks in advance for any help !
Hello there, this is my first post here and I’m writing because of problem with my boxster.
Today in the morning I’ve started my 2002 boxster and noticed strange sounds from the engine/ rear side of the car
It’s a metallic, grinding sound like a loose piece of metal or something like that
Sound disappears when you press gas and comes back once you loose the pedal, I don’t know if it changes while engine is warm
Also, check engine light shown up yesterday, when I connected my BT OBD2 there was no error code.
I came with that to workshop also, and they said it’s a catalyst efficiency error.
I’ve had that error code a while ago, I’ve replaced mass air flow meter and check engine light disappeared.
I think it might be a problem with maf again because I bought not the cheaper, not the original one, but why are there these strange sounds? I’m worried about this. Could it be catalyst this time? Or again should I replace maf? This time I’ll buy original one.
here are two Videos I made
Also I’m sorry if you can’t understand something, my english is not perfect.
Thank you for all replies, I hope we will solve that problem together
Have 03 C4S 55K mi. Both Cats going bad. getting CEL after every 50 to 75 mi. First from bank 1 and now bank 2. Have basic Torque App software to reset. Pain in Butt.
I track car about 3 times a year. No car mods. Run for fun.
Looking to boost HP via new performance exhaust system. Thinking Headers and Sport CATs from Fabspeed. Factory mufflers are original, seem fine and would like to reuse.
Along with perhaps new clamps, gaskets and a few new bolts, does anyone have advise on this?
I installed a complete Used FVD Brombacher exhaust this weekend. Headers, Cats, Mufflers, 02 Sensors. When installing the FVD exhaust I noticed that the post catalytic O2 sensors were on opposite sides of the stock headers. (2001 C2 Manual) The leads were not long enough to go to the opposite side connectors. So I plugged them into the sockets closest to them. I was able to drive for about 30 miles until the CEL light came on. I noticed the idle was a little off, would fluctuate between the 760 - 860 range I think . Car drove fine. When I got back home I checked the codes.
P01030 O2 Sensor Curcuit Bank 1
P1130 Oxygen Sensing
P1126 Oxygen Sensing
P0300 Random Misifre Detected
P0306 Misfire Cyl 6
P0304 Mis Cyl 4
P0305 Mis Cyl 5
02 Sensor Output 0.0v Bank 1 Sensor 1
I hope you enjoyed my drawings.
Would this be due to the post cat O2 sensors be plugged into the opposite connectors? Plugs and tubes were replaced about 6K ago, all the coils looked fine. The 02 sensors came on the exhaust. Could this just be a bad O2 sensor? Would it be advisable to get the DME re tuned for the new exhaust?'