Engine check warning light

Oh4show · Post by **Oh4show** » Sat Sep 14, 2019 11:48 am

Hi my engine check warning comes on and but goes out again sometimes ,when it's on the car idles ruff when sitting stationary can anyone tell me what this is , I have it booked in on Monday as I have 6 months rac gold membership on my e86.

Smartbear · Post by **Smartbear** » Fri Sep 20, 2019 8:04 pm

Oh4show wrote: ↑Sat Sep 14, 2019 11:48 am Hi my engine check warning comes on and but goes out again sometimes ,when it's on the car idles ruff when sitting stationary can anyone tell me what this is , I have it booked in on Monday as I have 6 months rac gold membership on my e86.

Hi, you need to get the codes read first or people are just guessing what the issue may be.
Rob

rhobson_897 · Post by **rhobson_897** » Fri Sep 27, 2019 12:43 pm

I have had the check engine light on mine, bought a code reader which suggested it was the o2 sensor Bank 1 Sensor 2, no activity detected (from memory). If I reset it it returns a short while later. I had the sensor replaced at the last MOT (as check engine light is now a fail, I was never to worried before). But again it returned shortly afterwards... Makes me think something else is going on. I have bought a bluetooth code reader which gives more info than my previous one. So hoping to be able to diagnose better soon. Someone suggested maybe its a wiring issue with a connector? Which makes sense to me

My trouble is I dont know where the Bank 1 Sensor 2 o2 sensor physically is on my engine? Can anyone help my locate it?

Piper1 · Post by **Piper1** » Fri Sep 27, 2019 4:39 pm

rhobson_897 wrote: ↑Fri Sep 27, 2019 12:43 pm I have had the check engine light on mine, bought a code reader which suggested it was the o2 sensor Bank 1 Sensor 2, no activity detected (from memory). If I reset it it returns a short while later. I had the sensor replaced at the last MOT (as check engine light is now a fail, I was never to worried before). But again it returned shortly afterwards... Makes me think something else is going on. I have bought a bluetooth code reader which gives more info than my previous one. So hoping to be able to diagnose better soon. Someone suggested maybe its a wiring issue with a connector? Which makes sense to me

My trouble is I dont know where the Bank 1 Sensor 2 o2 sensor physically is on my engine? Can anyone help my locate it?

Realoem.com will show location for sure. Bank 1 is for cyl 1-3 bank 2 is 4-6. Sensor 1 pre cat sensor 2 post cat. On my pre facelift M54 I had bank 1 sensor1 O2 sensor aging code thrown. Replaced it with NTK sensor and code showed back up couple months later. Replaced it with Bosch and 4 years and counting not come back so might be finicky to which brand O2 you had put in too.

Mr Tidy · Post by **Mr Tidy** » Fri Sep 27, 2019 8:37 pm

Soon after I bought my current E86 I got an Amber EML that got diagnosed as being post-cat sensors on Banks 1 and 2.

Got it reset by my Indy who chucked some Cat-A-Clean in it and suggested I ran it on Super-Plus fuel only.

A couple of months later and the Amber EML returned so I booked another diagnosis - the battery died during the diagnosis.

Codes cleared new battery and 2+ years later all is well.

So you might want to start with checking codes and also the battery before you get too involved with sensors, etc.

Hope it is a simple fix.

rhobson_897 · Post by **rhobson_897** » Thu Oct 24, 2019 11:09 am

Thanks for the responses. Interesting about the bosch o2 sensor lasting 4+ years... And the battery issue. Maybe I'll try using premium fuel aand the Cat-A-Clean stuff too.

Decided to check the connectors myself. Found some interesting cable tie positions on the cables but no obvious issues. Have sprayed some IPA cleaner on the connectors and cleared the code again. Hopefully will stay cleared...

I was mistaken above, the code is Bank 2 Sensor 1. I have only managed to find 2 sensors by the engine... I think they might be Bank 1 Sensor 1/2 though. Anyone have a good pic of where Bank 2 Sensors are, I can't see them... Ive checked realoem.com and it doesnt seem obvious. Maybe I need to remove the plastic engine cover to see them? Ive not tried that yet...

rhobson_897 · Post by **rhobson_897** » Thu Oct 24, 2019 11:28 am

[youtube]https://www.youtube.com/watch?v=7GJTgChpie8[/youtube]

Found this video, FYI not the greatest guide going, but shows the connectors (For Bank1/2 Sensor 2) seem to be underneath the plastic engine cover... And the o2 sensors themselves are hidden underneath the car.

So I had found the Bank 1/2 Sensor 1 on the side of the engine.

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