Misfire all cylinders bex

[ANDYMC_TQS]

hi all I’m sure it’s just a coincidence but I’ve done a few things to the car this week last of which was a cat back exhaust
and on the way home it started misfiring and when ever I came to a junction it was smoking like a train.

Here’s the relevant events leading up to it.
A month ago my exhaust snapped at the flexi so I parked it up over Xmas and used the missus car, I used it as an excuse to get a custom exhaust put on there so booked in for the sat just gone.

I decided befor I take it I would do the deletes I’ve wanted to do so last Tuesday did the sai delete, n249 bypass and pcv simplification, while I was there I changed the coolant temp sensors as my gauge has never read over 70 since I bought the car, I also found burnt connection on the thermostat plug and it had no thermostat so changed all that too

The car drove so much better after doing all that

On Friday I fitted my decat ready for the exhaust to be built of of that on sat morning, I drove home and to the exhaust place very slowly as was so loud and then on the way back it drove fine for a few miles and the above problems started, I’ve checked everything I’ve done and nothing has come off.

Sorry for the essay but wanted to give all info as may or may not be relevant
Thanks for reading

 

[QuattroCalum]

Can you scan for codes, you’ve done so much work making it difficult to try and find what/where it’s gone wrong.


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[ANDYMC_TQS]

Yes I had
Fuel trim bank one which has been on and off since I bought it
Various lambda founds I suspect due to the decat
Evap incorrect flow which I think is because I’ve taken loads of pipes out
Random misfire and misfire cylinder 1,2,3 and 4

 

[QuattroCalum]

Fuel trim that's an old code and obviously still relevant. What lambda codes are they? Post cat codes don't matter and are irrelevant but if it's the first 02 sensor (which I suspect) then your problem could be that, however it could also be from the pcv simplification as the crankcase gasses are routed to the inlet pipe as are the EVAP gasses, I don't know why people delete the EVAP as there is no performance gain, in fact you will lose some mpg by deleting it.
Post 02 codes can be avoided by fitting a 02 spacer in, such as https://www.ebay.co.uk/itm/RACE-EXH...628430?hash=item51fd931f4e:g:RBAAAOxyjxlTOpPT

I'm keen to help if you can find the codes. Did you block off the pipe from the EVAP to the turbo inlet pipe? This would allow unmetered air in and certainly cause a lean code.

 

[ANDYMC_TQS]

Yeah that’s why I have left the evap in place I have heard people get fueling problems from it.
I will have to drive it again to get the errors back as I deleted all to see if all the misfires return.
I will get one of those spacers ordered thank you, I did say to the exhaust builder could he fit one but he said it didn’t matter if I was planning on having it remapped, I did think well what about the time until then
The evap still runs to the inlet and the other pipe that runs behind the engine just goes to the inlet for a vacuum.
I will get the codes and get back to you

 

[ANDYMC_TQS]

Ok so I just went for about an 8 mile drive started off kangerooing down the road unless litterally ticked the accelerator, then it started to get a little better but still hesitant,
I held my foot down and it eventually went like the clappers.
Still smoking like a train when I pull up to a junction and I think on more observation when decelerating between 3 and 1k
The only errors I had when I pulled up were
P1118 lambda s2 open circuit
P1114 lambda s2 resistance too high
But I had disconnected that sensor yesterday to see if it made a difference thinking it was the post sensor that mattered.
And my usual
P1128 fuel trim bank 1 system too lean
Thanks again for your help

 

[QuattroCalum]

http://wiki.ross-tech.com/wiki/index.php/17526/P1118/004376

http://wiki.ross-tech.com/wiki/index.php/17522/P1114

http://wiki.ross-tech.com/wiki/index.php/17536/P1128/004392



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[ANDYMC_TQS]

Thank u very much the first 2 are definitely because I unplugged it
I will fit the spacer for the o2 sensor as soon as it arrives I think your right there it makes sense as only struggles at low revs when it’s closed loop and is fine when floored as going open loop and no longer cares what the fueling does.
As for the smoke I think I’ve sussed that as a different problem, I had forgotten that when I leave it idling for extended times it starts smoking and I think now there is no cat it’s making the problem a whole lot worse.......it needs a turbo

The fuel trim error I also remembered something else last night when I changed the plugs last year I noticed that my pistons are absolutely spotless no carbon at all

Again thank you very much for your help

 

[QuattroCalum]

The smoking could be the oil cooler, on my Passat 1.8t the smoke would come and go, no rhyme nor reason to it. Does it smell noxious/acrid, if so that’s burning coolant.
Glad to help


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[ANDYMC_TQS]

Smells a bit oily it’s only ever on idle it happens really there was a bit of play in my turbo I noticed and gradually been getting worse,
The lads at work think turbo from the smell but we are all Alfa/fiat/Jeep mechanics ha

 

[QuattroCalum]

Smells a bit oily it’s only ever on idle it happens really there was a bit of play in my turbo I noticed and gradually been getting worse,
The lads at work think turbo from the smell but we are all Alfa/fiat/Jeep mechanics ha

I have a turbo if you need one but it’s not BEX turbo, but it doesn’t smoke. You can let me know if you’re interested.


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[ANDYMC_TQS]

What kind is it mate I’m probably going to get a billet wheel hybrid as know a friend who knows a friend who owns a turbo shop and can get it for £570 which is pretty cheap

 

[QuattroCalum]

What kind is it mate I’m probably going to get a billet wheel hybrid as know a friend who knows a friend who owns a turbo shop and can get it for £570 which is pretty cheap

It’s just a K03s.


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[QuattroCalum]

Any further forward with this? I'm wondering if throttle body clean and alighnment would help?

 

[ANDYMC_TQS]

Yes it was my turbo, once I removed the cat it had less back pressure which was helping with the faulty thrust washer in the turbo. It had always smoked a bit when left to idle but once the cat (which had melted) had gone it allowed oil to pass through the inlet side and into the cylinders causing the misfire.
That and I think the o2 readings played a part due to not having the spacer fitted.
Not sure I’ve explained it the best sorry

 

[ANDYMC_TQS]

Thanks for the vid too I may do that anyway

 

[QuattroCalum]

Yes it was my turbo, once I removed the cat it had less back pressure which was helping with the faulty thrust washer in the turbo. It had always smoked a bit when left to idle but once the cat (which had melted) had gone it allowed oil to pass through the inlet side and into the cylinders causing the misfire.
That and I think the o2 readings played a part due to not having the spacer fitted.
Not sure I’ve explained it the best sorry

Ah okay, glad you have it sorted. The post cat 02 sensor only reports whether the cat is working properly while the pre cat sensor does the fuelling, well it would until it was contaminated with oil but that would burn off once you fitted replacement turbo. Thanks for your reply


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[ANDYMC_TQS]

No probs thanks for the help. New turbo arrives tomorrow with nice new billet wheel so will fit that, the spacer some new plugs and do an oil and filter change I think will let you know how it goes after

 

[QuattroCalum]

Your welcome, regarding the pre cat 02 sensor a good spray of brake cleaner and dried off with compressed air should help it. I would also give the intercooler a good clean as well, there's bound to be oil in there.