Seat Leon Emissions Help
Discussion
Hi.
Having some emissions related issues with my late 2014 Seat Leon 1.2 TSI CYVB. Hoping for some help.
Background: Had the car since Oct 24 @53k. Feb 25 had the cambelt replaced @58k. Disaster. Misfiring on all cylinders. Had it timed back up using VAS 611007 tooling all good. Misfired for a week or so while I found another garage, unfortunately had to use the car.
MOT Nov 25 @69k. Tester said it took 3 times to pass on CO would probably need a new CAT next year.
Quoted £2100 for a new CAT and told not to use an aftermarket one as it would only last a year or so... Put it off... Kept up with full service history.
Stinks of petrol through vents all winter. Sometimes eggy when reversing up to an enclosed space after 20+ mile drive. Slight rattle from under neath when revved (guessing could be loose substrate)
Apr 26 @76k EML comes on with code P111400 Bank 1 Sensor 2 Internal Resistance Too High.
Few Questions
1. Is £2100 steep for an OEM CAT?
2. Anyone used a BM Catalytic Converter and has it lasted?
3. Could the post CAT sensor just need changing?
In the history it had an oxygen sensor in Mar 24 @50k. Maybe this was a cheap one that's failed already...
4. Was the CAT likely damaged by the misfire or do they last this long on these Leons?
5. Has it likely been over fuelling, potentially causing other issues.
I don't want to throw a lot of money at this car. I feel this could be a recurring issue unless I replace the CAT and both sensors with OEM.
Tempted to part ex it but will lose £4k...
Any help appreciated.
Sorry for long post.
Having some emissions related issues with my late 2014 Seat Leon 1.2 TSI CYVB. Hoping for some help.
Background: Had the car since Oct 24 @53k. Feb 25 had the cambelt replaced @58k. Disaster. Misfiring on all cylinders. Had it timed back up using VAS 611007 tooling all good. Misfired for a week or so while I found another garage, unfortunately had to use the car.
MOT Nov 25 @69k. Tester said it took 3 times to pass on CO would probably need a new CAT next year.
Quoted £2100 for a new CAT and told not to use an aftermarket one as it would only last a year or so... Put it off... Kept up with full service history.
Stinks of petrol through vents all winter. Sometimes eggy when reversing up to an enclosed space after 20+ mile drive. Slight rattle from under neath when revved (guessing could be loose substrate)
Apr 26 @76k EML comes on with code P111400 Bank 1 Sensor 2 Internal Resistance Too High.
Few Questions
1. Is £2100 steep for an OEM CAT?
2. Anyone used a BM Catalytic Converter and has it lasted?
3. Could the post CAT sensor just need changing?
In the history it had an oxygen sensor in Mar 24 @50k. Maybe this was a cheap one that's failed already...
4. Was the CAT likely damaged by the misfire or do they last this long on these Leons?
5. Has it likely been over fuelling, potentially causing other issues.
I don't want to throw a lot of money at this car. I feel this could be a recurring issue unless I replace the CAT and both sensors with OEM.
Tempted to part ex it but will lose £4k...
Any help appreciated.
Sorry for long post.
stevemcs said:
Yes BM cats are absolute rubbish- you will get 1-2 years out of it, assuming it fits in the first place
When did it last have plugs ?
Hi, thanks for the response.When did it last have plugs ?
BM is the only new aftermarket I can find. Everything on Autodoc is out of stock. OEM used spare on ebay are around £200 and would be a gamble also.
It had plugs and new coils in Jun 25 @63k. The mechanic said "the coils fell apart when removed". A full set was cheap so I bet he didn't use the best quality.
When I got my Ancel VAG specific code reader Jan 26 there was a deep rooted code for misfire cylinder 2. It didn't bring the EML on. Cleared and it never came back. Was going to switch the coils if it did to see if one was faulty.
Swap the plugs and coils around and see what happens, we have seen plugs, injectors, fuel pump all cause emissions
The oil/fuel smell are are all of the breather lines intact ? I cannot remember if it’s the 1.2 or 1.4 there is a hose that comes off the air intake (filter) that usually gets snapped off, it then runs to the back of the cam cover rh side and it snaps off there
I would not waste money on a Bm cat. Better off with used oe.
Have you checked the resistance of the lambda sensor ? What’s the emissions like - have you got a print out from a mot ?
The oil/fuel smell are are all of the breather lines intact ? I cannot remember if it’s the 1.2 or 1.4 there is a hose that comes off the air intake (filter) that usually gets snapped off, it then runs to the back of the cam cover rh side and it snaps off there
I would not waste money on a Bm cat. Better off with used oe.
Have you checked the resistance of the lambda sensor ? What’s the emissions like - have you got a print out from a mot ?
stevemcs said:
Swap the plugs and coils around and see what happens, we have seen plugs, injectors, fuel pump all cause emissions
The oil/fuel smell are are all of the breather lines intact ? I cannot remember if it s the 1.2 or 1.4 there is a hose that comes off the air intake (filter) that usually gets snapped off, it then runs to the back of the cam cover rh side and it snaps off there
I would not waste money on a Bm cat. Better off with used oe.
Have you checked the resistance of the lambda sensor ? What s the emissions like - have you got a print out from a mot ?
Okay thanks for the help. At the weekend:The oil/fuel smell are are all of the breather lines intact ? I cannot remember if it s the 1.2 or 1.4 there is a hose that comes off the air intake (filter) that usually gets snapped off, it then runs to the back of the cam cover rh side and it snaps off there
I would not waste money on a Bm cat. Better off with used oe.
Have you checked the resistance of the lambda sensor ? What s the emissions like - have you got a print out from a mot ?
1. I'll switch the plugs and coils around, hopefully the coils come out easily. I miss simple HT leads...
2. I'll recheck the lines especially the area you mentioned. I had the purge valve off and that wasn't stuck open. Weirdly the fuel cap doesn't hiss like it used to when removing to fill up. At one point I thought maybe the charcoal canister was an issue but didn't explore.
Side note - I heard these have an issue with injector retention rail coming loose when a bolt shears due to hammering effect - but need to take the intake manifold off to check.
3. I assume Klarius is similar to BM. Euro Car Parts are now showing this in stock.
4. I'll try to check the resistance of the lambda sensor.
I ran a couple of CATAcleans through it just after the MOT. Probably a waste of time.
Emissions were
Fast idle 2000-3000rpm
CO - max limit 0.2% - reading 0.85%
HC - max limit 200ppm - reading 5ppm
Lambda - 0.97-1.03 - reading 0.98
2nd fast idle 2000-3000rpm
CO - reading 0.11%
HC - reading 15ppm
Lambda - reading 1.03
Natural Idle 450-1500rpm
CO -max limit 0.3% - reading 0.28%
Thanks!
Edited by S123 on Monday 13th April 21:27
Edited by S123 on Monday 13th April 21:32
I think I would take a risk with second hand oe but your never sure what your getting so it could cost you more in labour time etc if your having to swap them over unless your doing it yourself.
Aftermarket cats are generally crap and would only really make any sense if you wanted to just get through mot to sell and they may struggle with that to be honest.
You certainly need to be addressing misfires first though really as you could cook another one.
Aftermarket cats are generally crap and would only really make any sense if you wanted to just get through mot to sell and they may struggle with that to be honest.
You certainly need to be addressing misfires first though really as you could cook another one.
Belle427 said:
I think I would take a risk with second hand oe but your never sure what your getting so it could cost you more in labour time etc if your having to swap them over unless your doing it yourself.
Aftermarket cats are generally crap and would only really make any sense if you wanted to just get through mot to sell and they may struggle with that to be honest.
You certainly need to be addressing misfires first though really as you could cook another one.
I am leaning towards getting a 2nd hand OE CAT after doing the checks above. I would try to fit it myself. Never done any exhaust work before so tips would be welcome. Ill check out YouTube and I have the SEAT maintenance manuals downloaded so will check in there. I'm fairly competent, used to do my own servicing, suspension, brakes etc. Done a head gasket and camshaft before.Aftermarket cats are generally crap and would only really make any sense if you wanted to just get through mot to sell and they may struggle with that to be honest.
You certainly need to be addressing misfires first though really as you could cook another one.
Regarding the misfires. I'm not entirely sure what's causing them. It has a slightly uneven idle at times and pulling away on a cold start it can have hesitation for first 1/4 mile but no codes have come on. I'll switch the plugs and coils see if anything happens...
Used cat from a decent breaker who can ideally provide chassis number for vehicle it was removed from. Make sure car is fundamentally sound with history, MOT, not moon miles etc.
OE cats are generally good quality and last a long time so excepting abuse/neglect a used one should be fine for many years to come.
OE cats are generally good quality and last a long time so excepting abuse/neglect a used one should be fine for many years to come.
Dr G said:
Used cat from a decent breaker who can ideally provide chassis number for vehicle it was removed from. Make sure car is fundamentally sound with history, MOT, not moon miles etc.
OE cats are generally good quality and last a long time so excepting abuse/neglect a used one should be fine for many years to come.
Messaged some ebay breakers with similar cars listed for parts. Most don't have registrations listed/showing in photos so have politely asked.OE cats are generally good quality and last a long time so excepting abuse/neglect a used one should be fine for many years to come.
Guessing a lower mileage side crash damaged one would be perfect...
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