Exhaust warning light - Powervalve 200 cell

[AJP]

Just had the exhaust waring light pop up, in amber, not flashing. The car feels and sounds fine.

It's Stage 1 R-Tech with a full Powervalve (200 cell sports cat). Exhaust has been on the car for a couple of months and all has been well. I'm due to visit R-Tech soon to tweak the map to the exhaust, but this is purely for performance as the sport cat shouldn't bring up any errors like a decat does as we all know.

I know it's often a lambda issue that brings the light up, but could be a few other things. Just wondered if the fact the cat/downpipe isn't standard is relevant at all, although everything I've learnt tells me it shouldn't.

It's in at VW for a major service on Monday as it happens. I'm trying to decide the best course of action - if the light has cleared by then I might not mention it, I don't really want to pay dealer prices for what might turn out to be a sensor plus labour. Only reason I'm taking it to VW for the service is that it's had VW all its life, so I see some value in continuing that for when I eventually sell up.

Thoughts?

[Paradox1]

I was under the impression that even with a sports cat, you can still get the engine light on as the flow has increased. If the car drive as normal then that's what id put my money on. nothing to worry about, a map with sort it

[AJP]

I was under the impression that even with a sports cat, you can still get the engine light on as the flow has increased. If the car drive as normal then that's what id put my money on. nothing to worry about, a map with sort it

Do you know what code it'd bring up if that is the case?

I'd expect the light to have come on pretty much straight after the exhaust was fitted though, not months later.

[AJP]

@Powervalve Nige Any thoughts?

[Dan_FR]

Its the cat. Either fit the original or book it in with Niki

[AJP]

Its the cat. Either fit the original or book it in with Niki

Seems that's the consensus so far. Strange that it's taken so long for the warning light to show.

Obviously it'll be a trip to Hinckley rather than putting the standard cat back on!

[pudding]

I was under the impression that even with a sports cat, you can still get the engine light on as the flow has increased. If the car drive as normal then that's what id put my money on. nothing to worry about, a map with sort it

Do you know what code it'd bring up if that is the case?

I'd expect the light to have come on pretty much straight after the exhaust was fitted though, not months later.

"Sensor 2 - system too lean / rich" or something along those lines.

As above, it's the cat.  Sensor 2 is tuned to the factory cat(s).  Sensor 2 expects a different signal to sensor 1.  When both sensors see the same signal, it throws the fault code.  It won't, or shouldn't, affect how it runs but it's a good idea to get it coded out.  It's just an on / off byte in the ECU software.

This is the problem with aftermarket cats.  They are rubbish at catalyst duties but good for flow.

[AJP]

Cheers Pudding.

I'd have had the map updated by now, in fact I was booked in but had to cancel as the oem clutch was giving up. I'm all Helixed up now so I'll give Niki a ring after the service on Monday and get it booked in.

Should see a few more ponies from it too.

[pudding]

Yeah definitely.   You getting the standard throttle mapping put back on?  I am     I miss the aggression of my Revo map too much!

How are you finding the Helix?  Pretty good isn't it?  I've had aftermarket clutches before that juddered like hell but this one is smooth as standard!

[AJP]

Yeah definitely.   You getting the standard throttle mapping put back on?  I am     I miss the aggression of my Revo map too much!

How are you finding the Helix?  Pretty good isn't it?  I've had aftermarket clutches before that juddered like hell but this one is smooth as standard!

I'll just go with whatever throttle mapping he set the Stage 1 at, it feels good to me. Not sure what throttle map it is but it doesn't feel boggy or too linear, so I'm guessing it's not the 1:1 that some people don't seem fond of. Maybe that's reserved for higher output maps, k04 stuff?

That said, I am tempted to ask Niki to 'make it aggressive' as the Helix should handle anything a k03 can throw at it!

As for the Helix itself, it's spot on. Very good feel, no juddering, really positive pedal. It's heavier than stock but not massively. I was used to the pedal within about 20 miles of traffic.

[pudding]

Cool, glad you like it!

Yeah I would always go for maximum attack, but that's just me!   I like to overtake as quickly as possible, especially on B roads.  The 1:1 has definitely blunted that stab and go feel, but Ed30s aren't as punchy low down as K03s anyway.

[AJP]

Cool, glad you like it!

Yeah I would always go for maximum attack, but that's just me!   I like to overtake as quickly as possible, especially on B roads.  The 1:1 has definitely blunted that stab and go feel, but Ed30s aren't as punchy low down as K03s anyway.

I can definitely modulate the throttle comfortably. From what I gather some maps are a bit OTT on the throttle, so with the tiniest squeeze you're hitting full boost. But the R-Tech map I have doesn't have that 'on or off' characteristic, which suits me, although I never feel like I have to push the throttle too far to get the car to pick up. It's nicely balanced.

I'd imagine the smaller k03 helps to keep things responsive, like you say. Maybe a k04 car needs a slightly more aggressive throttle map if you want to get around the (marginally) more pronounced lag and maintain a sharp response.

There was a thread about this recently when Niki explained things. Much of that went over my head, but it makes good reading!

[pudding]

Cool, glad you like it!

Yeah I would always go for maximum attack, but that's just me!   I like to overtake as quickly as possible, especially on B roads.  The 1:1 has definitely blunted that stab and go feel, but Ed30s aren't as punchy low down as K03s anyway.

I can definitely modulate the throttle comfortably. From what I gather some maps are a bit OTT on the throttle, so with the tiniest squeeze you're hitting full boost. But the R-Tech map I have doesn't have that 'on or off' characteristic, which suits me, although I never feel like I have to push the throttle too far to get the car to pick up. It's nicely balanced.

I'd imagine the smaller k03 helps to keep things responsive, like you say. Maybe a k04 car needs a slightly more aggressive throttle map if you want to get around the (marginally) more pronounced lag and maintain a sharp response.

There was a thread about this recently when Niki explained things. Much of that went over my head, but it makes good reading!

I think I know the thread and it does make sense

What he said about the R32s being mapped to feel quicker than they really are, it's true.  Thing is though, I tried a 1:1 throttle on mine and it was horrible.  A completely different car.  Zero balls below 3000rpm.   And it's a similar story with my Ed30.  Sure, it's not going to have quite the same kick as a 3.2 litre below 2500rpm, but the standard map was definitely a lot sharper.  I like the 'placebo' mapping 

From my own data logging, I've seen where advancing the intake cam a lot more than standard could help the areas 'under the curve' (off boost in other words) so I might get my mapper to try that.  I like everything to be as responsive as possible.  Being ultra responsive is the best the engine can be, so it's like making it worse on purpose....like turning the sport button off (if we had one!).  I get it that not everyone wants their neck snapped when they breath on the throttle though 

[AJP]

That's the beauty of it, with custom mapping we can specify how we want the car to feel. It's a subjective thing, what one person finds slow and boggy another person finds ideal.

We're a bit spoilt when it comes to mapping options. I remember years ago you'd have a new chip soldered in and that was that!

[pudding]

That's the beauty of it, with custom mapping we can specify how we want the car to feel. It's a subjective thing, what one person finds slow and boggy another person finds ideal.

We're a bit spoilt when it comes to mapping options. I remember years ago you'd have a new chip soldered in and that was that!

Lol I remember those days well!  And carburettors, just!  Messing about with jet sizes and stuff and usually making it worse 

Very true though, there are no wrongs or rights when it comes to tuning, just preferences