Running a catless x-pipe without a tune?

[E92Bean]

I have a corsa rear section and am interested in running a BW x-pipe. Mainly for sound, but it’s also the best HP mod for the s65. However, I have an engine+trans warranty, so I’d hate to tune the car, have something blow up, and deal with having coverage denied (I’ve considered flashing to stock if that happens, but would there be evidence of it being tuned?)
Am I correct thinking that the car will pickup some power, but a tune will optimize power gains and shut off the CEL?
I would just wait until my warranty ends, but I’m looking at a used system.
I’ll be going with epic motorsports down the line.

[PandaM3]

You can try running O2 spacers so no cel

[VR1]

From my experience with my 3rd party warranty, my shop reccomended I swap my stock x pipe on for warranty claims anyways (I’m catless). If I were you I’d just do the tune and then swap back to stock x pipe and flash back to stock if you need to do a claim.

[M3SQRD]

When does your engine-trans warranty end? If it’s months away then I’d wait but, if it’s years away, I’d install the tune and x-pipe. The Epic tune + BW x-pipe will definitely wake up your engine! The increased 8600 rpm redline makes a noticeable difference and the engine just feels like it wants to keep on revving right past the new redline. Reflash back to stock if needed without leaving a trace.

[E92Bean]

Originally Posted by M3SQRD

When does your engine-trans warranty end? If it’s months away then I’d wait but, if it’s years away, I’d install the tune and x-pipe. The Epic tune + BW x-pipe will definitely wake up your engine! The increased 8600 rpm redline makes a noticeable difference and the engine just feels like it wants to keep on revving right past the new redline. Reflash back to stock if needed without leaving a trace.

It ends in 2 years, so I may go that route. I do think it’d be a little annoying to swap x-pipes in cases of catastrophic failure or TA’s. My contract would deny claims if the software has been manipulated, but would they care about an aftermarket x-pipe and O2 spacers?
A benefit of tuning it would be that any impending catastrophic damage could be done within my warranty, but it’s just more work to get back to stock.

[spammysammich]

There have been drivability issues reported with forward x pipes and no tuning. Stumbling and hesitation on throttle among the complaints.

[DrFerry]

Originally Posted by spammysammich

There have been drivability issues reported with forward x pipes and no tuning. Stumbling and hesitation on throttle among the complaints.

Good points. Sometimes a rough idle too.

[omgzirra_exe]

Originally Posted by DrFerry

Good points. Sometimes a rough idle too.

yeah, it works great when it does, but i also can't get passed the sound a forward X makes also..

works great with specific mufflers though.

but back to the main topic, just keep your OEM xpipe and swap it when the time comes for warranty and hope that time never comes.

[spammysammich]

Originally Posted by DrFerry

Good points. Sometimes a rough idle too.

Previous owner of my car apparently tried the BW x pipe and had that, stumbling on acceleration, and other symptoms that mimicked fuel vent valve issues so he changed injectors, coils, low pressure fuel sensor, vent valve and the alternator trying to track down the issue. Ultimately going back to a stock position x fixed it, then he decided to ditch the cats and put a Dinan stage 2 on it.

[DrFerry]

Originally Posted by spammysammich

Previous owner of my car apparently tried the BW x pipe and had that, stumbling on acceleration, and other symptoms that mimicked fuel vent valve issues so he changed injectors, coils, low pressure fuel sensor, vent valve and the alternator trying to track down the issue. Ultimately going back to a stock position x fixed it, then he decided to ditch the cats and put a Dinan stage 2 on it.

The forward X configuration probably alters the pre and post O2 sensor voltage readings in certain low rpm, low scavenging, situations due possibly to altered back pressure and the positioning of the O2 sensors.

[E92Bean]

Originally Posted by omgzirra_exe

yeah, it works great when it does, but i also can't get passed the sound a forward X makes also..

works great with specific mufflers though.

but back to the main topic, just keep your OEM xpipe and swap it when the time comes for warranty and hope that time never comes.

Yeah I’ll just keep my OEM pipes around. The forward X is great for power. The one I’d buy has several resonators added to reduce the rasp too.

[pbonsalb]

I would not go fully catless unless tuned. It will run rich and smell and not make much more power. A tune, even if flashed back to stock, can be detected because data stored in the ECU are out of the normal range. Just do secondary cat delete, which causes no problems. Swap the stock X pipe back in if you need to go to a dealer for servicing or have a warranty claim.

I usually end up modding my cars before they are out of warranty. Sometimes I have managed to wait a year or 2, but that is about it. Obviously, there is a risk and you have to accept it -- probably could not swap in a used S65 for less than $10k.

[RalliartRsX]

The stock compensation or VE tables are based off a catalytic converter being in the loop. Essentially, with no CAT in the loop, the ECU assumes the CAT is faulty and changes fuel trim and timing values to compensate.

In short; do not go catless unless you are tuned. Doubt it will do any mechanical damage, however, I am not aware of what operating conditions (fuel trim and such) the car reverts to if it assume a CAT is faulty

Just my .2c.........