Help! Engine runs rough and cuts out!

[samhalsey]

Firstly, I would just like to thank you lot for all your help in the past, all I seem to do on here is ask for advice! Now, I'm in need of some more advice 😂

Car was running a bit sluggish, low power in low revs etc. Felt like the cat was blocked, could also hear it rattle. swapped that out for a dc sports 4-2-1 and just did away with it. Now me being clumsy, in the process I dropped the o2 sensor (which I think was on its way out anyway). But the car started and ran fine a couple of times. Then all of a sudden, it would only start with the throttle slightly open, and when it did run it was rough as anything, stinks of fuel, then would cut out as soon as you let off the throttle.

I tried cleaning the o2 sensor in petrol. Didn't help, so I bit the bullet and got a new sensor. The denso one from torque GT.

I fit the new sensor, went to start the car fully expecting it to be fine, and it's exactly the same, rough, over fuelled and cuts out. Is it just that I need to remove any error codes, or disconnect the battery for a bit to reset the ecu. Or could there be another issue I'm unaware of?

Any help would be greatly appreciated as I'm aiming to get it to mimms on Sunday! Haha

 

[Chewy]

It could be something as simple as it's running lean and the ECU hasn't adjusted (As there is a slight tolerance it can adjust to) but seeing as you were having these issues before changing anything I wouldn't think this is the case....If anything if it was running lean before hand and you swapped out the manifold/changed the 02 sensor the AFR could be out.

Disconnecting the battery to reset the ECU as you said would be a good start just to cross another thing off the list until further suggestions come about.

Anything else been changed on the car, RBC? is it mapped? etc

 

[Johngreen537]

Management light on? Is it misfiring or just cutting out?

Disconnect the b pipe from the mani to check there's no issues with anything further down the exhaust.

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[samhalsey]

It could be something as simple as it's running lean and the ECU hasn't adjusted (As there is a slight tolerance it can adjust to) but seeing as you were having these issues before changing anything I wouldn't think this is the case....If anything if it was running lean before hand and you swapped out the manifold/changed the 02 sensor the AFR could be out.

Disconnecting the battery to reset the ECU as you said would be a good start just to cross another thing off the list until further suggestions come about.

Anything else been changed on the car, RBC? is it mapped? etc

It was running perfectly until one day it decided to start running funny. It has a k&n typhoon induction, and a full exhaust system now, but otherwise on that side of things it's all standard. Still on the oem ecu for now so no map. Although when I originally got the car 3 years ago it had a very similar setup, and ran fine. im hoping it is something simple 😂

 

[samhalsey]

Management light on? Is it misfiring or just cutting out?

Disconnect the b pipe from the mani to check there's no issues with anything further down the exhaust.

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Eml is on, but I believe that's because the secondary o2 readings are off because of the decat. And the car was running perfect until about a week ago, so I have a feeling it's not from the cat back. It was a sudden change, which is what's leading me to think it's a sensor somewhere

 

[Johngreen537]

What codes are logged in kmamager?

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[samhalsey]

What codes are logged in kmamager?

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Not had a chance to get a reader on it yet, I'll try get to it tonight if I can

 

[Torque GT]

Potentially a faulty fuel pressure regulator? Would explain why it stinks of fuel and won't run without the throttle open.

 

[samhalsey]

UPDATE! Only error code im getting is for the secondary o2 sensor. I erased the code anyway, no better. I disconnected the battery for 10 minutes to reset the ECU and now the car will not start at all. Now this has happened everytime my battery has gone flat, or been disconnected. And if im honest, i dont know what ive done to get it going each time, just persistent trying over matter of days and it eventually starts. Am i missing something obvious here? has any one else had issues after disconnecting the battery.
thanks
Sam

 

[spooke]

UPDATE! Only error code im getting is for the secondary o2 sensor. I erased the code anyway, no better. I disconnected the battery for 10 minutes to reset the ECU and now the car will not start at all. Now this has happened everytime my battery has gone flat, or been disconnected. And if im honest, i dont know what ive done to get it going each time, just persistent trying over matter of days and it eventually starts. Am i missing something obvious here? has any one else had issues after disconnecting the battery.
thanks
Sam

Do you get dash lights at all? Can you hear the fuel pump prime, is it turning over?

 

[samhalsey]

Do you get dash lights at all? Can you hear the fuel pump prime, is it turning over?

Only the normal start up lights, can hear the fuel pump and it turns over, just won't fire! It almost sounds like it's trying to, but won't

 

[SamDC5]

Get it on diagnostics, it'll tell you straight away.

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[DC5RLY]

Any update on this?

I'm having very similar issues at the moment.