EML with Top Gear exhaust??

Hi all, I've got 200 cell cats, sports boxes and new lambdas but I'm getting the EML coming on every few drives now. I've contacted TG who have suggested that they're not getting hot enough quickly enough but as it's my daily driver used for my 30 min, 30mph if I'm lucky commute, I don't know what I can do. Any (sensible :lol suggestions that don't involve morning speeding fines? Thanks

Perhaps there is a problem with your primary O2 sensor. Is your car tuned ?

Have you connected a scan tool to see which sensor is setting off the EML? If you have o2 sensors fitted post cat (early cars didn't) then it's likely these are being set off by the less effective sports cats as they think your cat efficiency isn't up to scratch (which it isn't, but you want it that way!). Options are either ignore the light, which won't affect performance but does mean you might miss it if something else more serious crops up. You could fit some lambda spacers which are widely available on Ebay, get them coded out or as a last resort fit the old cats back on. Or get a bicycle for that morning commute and get fit as well as not knackering your car on a short commute! :bandit:

I've got the same setup as the OP (except mine are xpipe cats) & fitted the parts myself & opted for new sensors as I wasn't prepared to try & reuse the old ones. In all honesty I've never had an EML, even after first fitting the exhausts & bedding it in. Without stating the obvious, are all the joints well sealed on the system as my techie commented when I had my engine out that he used OEM exhaust gaskets instead of reusing the Topgear ones, even though I'd not had any issues.

Thanks all, I did fit everything myself and was pretty confident with the fit, I did use plenty of paste but also the TG gaskets ?? I'll have a look at those spacers though Thanks

You haven't mentioned what the actual fault codes are .. Post cat warm up fault codes and yup its the cats .. spacers should fix this . Anything else and probably not . 200 cell cats are obviously less effective than the standard ones , they take longer to stop the post cat lambdas switching ( rich / lean ) and as such the car responds to this by bringing on the eml .. save the planet stuff as post cat has no effect on the running of the car . A spacer lifts the lambda sensor giving it a smaller mixture / airflow flowing over it .. it mimics a correctly operating cat . Not trying to teach anyone to suck eggs here

Thanks deMort, I didn't take note of the code when I reset them :sad: No doubt they'll be back soon and I'll post again.

I had this regularly on my 996 with the TG 200 cell cats. I fitted two 90 degree spacers to the lambdas (or rather had the garage do it) and the problem never reappeared.

I've had this on my GT3 ever since buying it. (I'd wondered why there was a code reading disc and cable in the boot when I bought it :hand: ). Every half a dozen cold starts or so, I get a P2098 code - Post catalyst fuel trim system too lean bank 2. I have the Cargraphic full system with manifolds and 200 cel cats, which we decided early on is obviously what's causing it. Fuelling been checked and all is fine. We did fit a new post cat lambda sensor on the offending side at the last service for good measure, but I got the fault last time I drove the car. My problem is either the cats (most likely) or a slight blow at a join , drawing in a bit of unmetered air. The Cargraphic system slides together like a motorbike system with springs pulling the parts together. So there could be a tiny leak at a join as no paste is used. It's more than likely the cats though. Basically, I just live with it and pull over to wipe the code if it appears, but my car isn't a daily driver. Dave do those spacers not cause the exhausts to get a bit sooty? My Indy said that by moving the sensor out of the airflow they don't read correctly and can run rich. I looked at them a year ago and decided to just leave as is, as like I say, all the fuelling is within limits when checked on the PIWIS. I could just fit a standard system but it sounds so good as it is.

It was the secondary sensors after the cats - I never noticed the pipes getting sooty but I did keep on top of cleaning it. The fact the EML didn't come on and scare the beejesus out of me was enough for me. I had an Android HU running the Torque app and a Bluetooth OBD plug so could scan and reset the code on the move.

The post cat sensors are solely there to assess the effectiveness of the catalytic converter. It's the pre cat sensors that control fuelling as they have access to the exhaust straight out of the engine. If fuelling was to be based on the post-cat exhaust it would be all over the place because most of the unburnt fuel is converted to CO2 so the sensors couldn't tell now rich or lean the car was running.

Yep, same here, post cat sensor. I use the little OBD plug thing with the Car Scanner app. I think it was recommended by KurlyKris on here. I'll probably just continue as I am. There's no risk to anything but as you say you get a bit of a fright when the light comes on. :grin: I was responding at the same time there Shal. Exactly, it's pretty unimportant. I'm guessing you also mean that the pipes won't get more sooty. In that case I may try a pair of spacers for next year, if I still have the car.

I have the TG 200 cell X-pipe along with switchable back boxes and also get this issue every few drives. My fairly old code reader usually returns an N/A for one code and P0156 O2 sensor circuit malfunction (bank 2 sensor 2). Sometimes I only get the N/A and once I've had P0136 P O2 sensor circuit malfunction (bank 1 sensor 2). According to my notes it has come on more often than not on wet days but I suspect that's coincidence. My indie has tested the O2 sensors and thinks they're fine in themselves (no adverse readings) and thought it may be a MAF issue. It's only mildly irritating and doesn't seem to impact performance at the time it comes on but I had started a thread about it on here a few months ago.

It's very likely the cats. The cheaper the 200cel cats (inside) the worse it will be. Top Gear ones amoung others have had many people report this issue. Quality of the fuel, driving style etc all has an impact too. When repacking my original cats with carnewal 200 cel ones (which have very high quality innards) just to be safe we changed the ECU parameters to slightly increase the tolerance to avoid any check engine lights which are a pain with MOT's etc. If spacers work that is another solution also but I haven't tried that myself.

I had the same with Kline system on my old C4s. Would pop up the EML every now and again. Not had any issues with mine on the C2 but its only has the two lambdas.