Got RPW headers installed, and were fine until just recently.
Also have had a bracket welded in upon installing, to stop the front and rear pipes from rattling on each other.
Like I said, it was fine for maybe 3 or 4 days, and now I have a rattle only when I flog it and the car jerks back.
Comes on around 5000RPM.
Not really sure what it could be

I removed the heatshield above where the dummy cat used to sit as it would vibrate & annoy the hell out of me.

The firewall side are very badly fabricated.
The welds have been done by an apprentice on his first work experience day...(or by the local crack dealer?)

Even if it isn't that on this occasion, you may as well remove them now and fix the welds.
It will bust your chops getting to the front exhaust manifold nut...it all has to come out.
Your knock sensor will interpret it as pinging, then goes into limp mode intermittently or worse stuff your engine.

And to top it all off your car isn't emissions compliant anymore, it drones, and doesn't get any significant performance improvement on the dyno.

Sorry about the rant, I just hate the bloody things to death.

Is it a case that the factory exhaust setup is better engineered than something aftermarket and is close to optimal anyway?

The days of exhaust systems choking an engine are long gone; putting on something that looks like a bag of snakes and glows in the dark improving power dramatically, those days are also long gone.

Still got the original bits?

John, This one of those rare times I agree with you 100%.

The build quality of these things is deplorable and they dont make a hell of a lot of difference aside from noise.

Add to this with the 2 pre cats removed the car is no longer compliant, we had the main cat tested by CCC Cat Converters and it is not much more than a dummy cat, there are no precious metals inside it at all, the OP has had another cat fitted however I doubt that the emissions will be anywhere near spec

I disagree with both you guys.

Here are two dyno charts, same cars, same mods except mine had extractors. Yes they were on different dynos (although same make) at different tuners but Richard also had his dynoed at CNJ which i used & it was within 1KW of the figure he had at Chiptorque which indicates they were reading very similar.

http://i189.photobucket.com/albums/z179/Krossbolt/Car%20Pics/My%20Car/147a.jpg

http://i253.photobucket.com/albums/hh60/foozrcool/Dynochart-1_zps98195894.jpg (http://s253.photobucket.com/user/foozrcool/media/Dynochart-1_zps98195894.jpg.html)

One thing I do agree with is the dodgy quality of the rear bank pipes, I had mine repaired & strengthened which hopefully should see Kif out. Mine were one of the original sets & have done a lot of K's pretty well trouble free.

Re the cat, it's well known the stock under cat is just a dummy & anyone removing the stock headers with the precats I'm sure has installed a replacement cat underneath to comply with emissions.

The OP has just done the extractors, no other upgrades as you did....so not quite the same experiment....


He could have taken a hammer and smashed out the ceramic catalyst out of the factory precats and had the same amount of flow in my opinion...and the same power gains...LOL

The emmisions would be identical too :)

Exactly, punching out the guts of the precats would also provide a similar "increase" in power.

My point is it does make a proven dyno increase in power & isn't a waste of time for anyone in search of power.

Even my Lexus which has a very similar precat setup, has been shown to increase power by a similar amount as the 380 when headers are installed. There are several forum members who have posted dyno charts on the Lexus.

I had the same issue with RPW Extractors many years ago. I rang dave many times at RPW and he was rather unhelpful untill i informed him that i know he gets them made in Sydney and want to take them back to the place that made them to be rectified as i live 30mins away from them. Turned out to be the flex join. They replaced it and all was good. Would rattle like Hell when you put your foot right into it. Its odd as Liverpool Exhaust in Sydney do alright so i dont know why these RPW ones are rubbish. RPW must be getting them to make $50 systems and sell them for 500.

Yep, one of the flexi joints on my 380 RPW extractors cracked internally. No noise, just exhaust fumes in the cabin whenever I gave it a good dose of right foot. Took months to discover this was the cause of the exhaust fumes. Luckily for me my exhaust bloke replaced both flexi joints free of charge.

I guess some credit has to go to RPW for at least having a go at some sort of performance mod for the 380.

The pickings are pretty slim for the 380 platform.

I'm going to come at this pretty even handed. I cannot comment on the quality of the headers, but I got to give them credit for having a crack. And the reality is, if they want to continue selling the product they need to improve the quality. Vote with your wallet I say.

Maybe one day we'll see a functional, quality, set of headers for the 380. Which would be great in my opinion.

The emissions thing bothers me though. I'd hate to shell out for headers only to shell out again for a fine.

I replaced my third "dummy" cat with a 200 CPI stainless steel cat. In attempt to cure the dreaded drone I later replaced that cat with a Magnaflow 350 CPI cat, and I reckon that would have been legal for emissions. But I don't know for sure, never had either of them tested. All my research at the time told me that a 100 CPI cat is illegal but a 200 CPI is OK. But that might just be for cars that come with a single cat from the factory, and not the stock 380 set up.

Sorry for the late reply. Been on holiday for the last few weeks.

So to update, I feel as though it may not be a crack in the extractors, because the rattling only occurs at very high rpm. Also, if I am already cruising at say 80km/h and floor it, there does not seem to be any rattle whatsoever. It seems that it only occurs at high rpm when the car jerks back due to acceleration. Might have to jack the car up and check the clearance of the whole system.

On a side note, I installed extractors and a 2.5" into dual 2.25" exhaust, all in one hit, and have not noticed any significant gain in power or torque whatsoever. The car feels very sluggish and slow. Sounds great, but just not what I expected for the amount of performance parts that were installed.
Fuel economy has also turned to s**t, but will hopefully get better once I get a piggback.

Thanks for all your responses :D

have not noticed any significant gain in power or torque whatsoever. The car feels very sluggish and slow. Sounds great, but just not what I expected for the amount of performance parts that were installed.
Fuel economy has also turned to s**t, but will hopefully get better once I get a piggyback.


Sounds like the oxygen sensors aren't doing their job. I vaguely remember others having that problem with aftermarket exhaust bits on the 380.

Sounds like the oxygen sensors aren't doing their job. I vaguely remember others having that problem with aftermarket exhaust bits on the 380.

Could it also possibly be that because the car isnt tuned, and the AFR's are around 9.5:1 at WOT that I could've already melted the cat due to the engine running so rich and caused a bit of a blockage in the system?

Just wish I could get the car running the way it should be with the mods that it has

Just a note, I've been running the car with no rear o2 sensors as i still need to have these extended, and they shouldn't affect performance at all as they are only there to measure emissions.
However, after some inspection, I have found that the front bank primary sensor has actually been unplugged....and instead, the rear o2 sensor which is meant to be fitted behind the cat, is installed straight into the headers (No idea how the exhaust shop could get something wrong like this). I'm assuming this would explain my power issues, as the ECU wouldn't be getting a proper reading from the front bank.
Or am I wrong, and all the sensors are exactly the same, just the placement of them changes?

Also, by running the rear oxygen sensor in the header itself, is it likely to burn itself out as it isnt used to running as the primary o2 sensor?

The O2 sensors are all identical, but which plugs they connect to and how the ECU reads them is different, so each one must be connected to the right plug.
Connecting up a rear sensor to a front sensor plug (ie one in the extractor) seems very dodgy to me.
I reckon if you plug the front two sensors into the correct plugs your AFRs, performance & fuel economy will all improve a lot.
As you say, the two rear sensors are all about emissions so even if they are missing/faulty/not working it shouldn't make any difference to power or fuel economy.
That was my experience anyway, even after fitting 'extenders' for the rear two sensors they never seemed to work as they should, per the multiple repeated "O2 sensor heated circuit" error codes I got, but I never had a problem with poor power or fuel economy.

That makes sense. Thanks for that.
Is there any way to know which plug correlates to which sensor?


after fitting 'extenders' for the rear two sensors they never seemed to work as they should

I've heard that most people have this problem regardless of their attempts to fix it, but I do believe Fooz had it working for a while until he added methanol injection to the system. So i figured it's at least worth a try. If not, I'll cover up the CEL like you both had done

I remember that each O2 sensor wire was a different length. IIRC the shortest one went from the front bank exhaust manifold to the nearest plug, the next longest one from the rear bank exhaust manifold to the next nearest plug, then the other two are the rear sensor wires. But I'm going by memory here, the only thing I'm quite sure of is that each of the four stock wires is a different length. Best bet would be to have a squiz at a stock 380 and see which wire connects to which plug.

Had a look, and you can't plug the wrong sensor into the wrong plug. The rear sensors have a different plug to the front sensors as one has a female connection and the other has a male connection.
Having said that, I know for sure now that the ecu isn't getting a reading from the front bank, as the sensor that is inserted into the front extractor is plugged into the plug that is meant for reading emissions.
Will post an update once sensors have been extended and placed in their proper positions.

Just an update on this:
I extended the front primary sensor myself, and have plugged it into the extractors (extended it a bit too much and have a bit of slack that i needed to cable tie out of the way).
This seems to have fixed the fuel consumption considerably. Gone from high 15L/100km, to 12.8L/100km.
So the issue with being low on power and running extremely rich has all seemingly been fixed.

As for the rattling. The headers and the welds are all in tact. No cracks that can be found. No leaks in the flex pipes (might have got a lucky set from RPW..), however the rattling was due to the main collector just before the cat, rubbing against what I can only describe as almost a cross member brace that runs below the exhaust tunnel of the car. Added a few washers to drop it a bit further away from the exhaust pipe and have since not experienced a single rattle.

Car is finally running the way it should be, and can finally appreciate the power gains.
Also the slight raspiness from the extractors is really starting to grow on me.