Hi everyone. I have had my V6S (non switchable active exhaust) for about a year. I think it's late 2015 model. it's out of warranty
hasn't been quite right since I bought it and I gradually found out the PO did some mods. seems it was chipped and the exhaust modified with higher flow cats and an attempt to jam the exhaust valves open somehow

The problems from these were:

1. poor throttle response. depress pedal and literally nothing happens then power comes on jerkily. low end torque seems down. power delivery poor
2. exhaust sounded bad. excessively raspy, constant (i retrospectively think these had been jammed the wrong way somehow and that the car had been always "closed"

I took it to an independent jag specialist in Melbourne who tried valiantly to fix the exhaust issue- unjammed the valves and fixed some exhaust leaks. also fixed some exhaust rattle from poor clamping. The exhaust is better- now the valves are open on startup, close at about 1500 and open again at 4000. The car sounds amazing with valves open but excessively raspy when close (which is most town driving). unfortunately it has caused a new problem which is a terribly scraping noise from both sides when the valves open/close (he said he tried to lube them but they had been stuck in one position for years).

said nothing could be done about the chipping

now:

1. ecu chipping related drivability issues
2. exhaust sounds good when open but are closed a lot (and not switchable)
3. terribly valve noise everytime they open or close

Questions:

1. can anything be done about the ecu? can it be restored to factory? re-done by someone reputable?
2. is there a (reversible) way of keeping the valves open? i pulled f43 fuse but this does not change the valves (ie they continue to open and close as per engine map

appreciate any input!


g

 

Unfortunately, it can be expensive to undo ricing. You will have to first understand the mods, then source replacement OEM parts. Of the key concern is undoing ECU tuning mods, as this reportedly creates drivability issues. Bad ECU mods can damage your engine, so take this as #1 concern. The go-to ECU tune for these cars is typically VAP, I recommend you contact them with your VIN and ask about your car, maybe Stuart will be kind enough to help you understand what was done and flash back to stock . Another common mod that is typically done along with a tune is supercharger pulley. If both were done, you cannot revert to OEM tune.

OEM exhaust is, I think, $4K for rear box with valves new and if you have to replace cats probably another couple K. There are after-market alternatives that are cheaper and reportedly of good quality. High-flow cats tend to be garbage, your car will pollute more, throw codes at random for meager performance gain at full RPM. There is really no reason for this mod, as OEM exhaust when open is not restrictive. However, it is cool thing to do and ricers tend to throw good money to have all the posers mods chekboxed. I would also check to make sure PO didn't slap K&N engine intake filter mod, another typical ricer mod that is harmful as it doesn't offer proper filtration unless filters are regularly cleaned and re-oiled.

Last but not least, if you purchased the car with mods not reported, you may have a case to go after PO. Undisclosed mods are "damage", unless the car is sold as-is. You might have a case for compensation or ask PO to pay to reverse them to stock.

 

thanks a lot for that great info mate.
i will contact VAP but I’m in Australia. I’m wondering if anyone knows anyone really good at this stuff in Melbourne?

Also, is there a way of telling if the SC pulley has been changed? Is it easy to change back?

Thanks g

 

you do not need a tune to do a sc pulley and if done I would leave it alone, its fine. And there should be no reason I can think of that a dealer cannot just upload latest ecu software and remove the modded one. And you're looking at a 1 hour charge normally for software updates

 

I recommend stuart at VAP, and if you can't find an OEM tune, get one of his tunes, they are spoken very highly off on this forum, you can make it so its not aggressive and safe for the motor, but do thinks like add more pops and bangs, etc etc. The VAP axle back is also awesome, the valvetronic one or the passive one, both good choices to replace your damaged rear back box, if your still experiencing rasp, go to a reputable exhaust shop and install some resonators, like vibrants. This should make it less raspy and clean up the sound, if you do not care about having valves, remove the rear muffler and replace it with 2 resonators and that should also improve the quality of the sound and rasp, and avoid having closed valves. A car that has high flow cats, tune, exhaust and pulley's is also making over 100 more horsepower then stock so the car will be a lot quicker and respond better then stock.

 

Adent,
When you say chipped, what do you mean? Was the ECU flashed, or was a RaceChip or similar installed. If the latter, an independent mechanic should be able to remove it. If someone flashed the ECU, I doubt Stuart at VAP will be able to help as he needs to start with an OEM tune to create an enhanced one. You can ask a dealer to flash back to an OEM tune, but that may end up bricking the ECU and you’ll need to spend US$1200 to buy a new one. To get where you want to be on the exhaust, you will need to revert back to OEM cat pipes to remove the raspiness, and I would suggest buying the VAP ValveTronic exhaust to replace your current one. (Holiday sales coming up in December). You might also be able to find a used exhaust from a wreck that’s being parted out. Don’t worry about the SC pulley. It offers a bit of hp and torque advantage without throwing any codes. Besides, it is impossible to find an OEM pulley without buying the whole supercharger.

 

thanks for this info everyone. work in progress...