Hey all, long time lurker, first post.

I’ve read some older posts on this same issue but figured to share my specifics in case you have some insights.

Background info: 2006 r53, 100k miles. Around 5 months ago I had my DSC go on, car had major power loss, then maybe 1 hr later didn’t start at all. Towed to my mechanic and all spark plugs replaced as well as the coil pack. Seems to do the trick, but then a few weeks later, same issue (could still drive, but major power loss). Coil pack replaced under warranty, seemed to fix it.

Just yesterday- I’m about 100 miles from home at a hotel and my DSC light went on. Car drove normally. Plugged in the ODB and it returned a P2300. Turned the car off, turned it back on, DSC is off, I cleared the P2300 and it drove normally and it didn’t return.

Today, DSC back on, service engine soon is on, plugged in the OBD, and it returned just a P0300. I think I feel the misfire at idle and low RPM, not sure about high RPM.

I’m a little concerned as I’m 100 miles from home and have a random misfire.

I read some posts on this and am wondering if this might be anything I can fix myself, like a new MAP sensor?

I’d greatly appreciate any insights at all!!

 

Throwing parts at it probably won't help, but you could get lucky. You need data to find out what's causing your misfire since many things could be causing the P0300 code. Pull up your fuel trims with your OBDII tool and report back what your short term fuel trim (STFT) and long-term fuel trim (LTFT) numbers are at idle, 1500 rpm, and 3000 rpm. Fuel trims will be in the OBDII live data menu on your tool if your tool supports live data.

You could also drive to an autozone and have your charging system checked. From your description, it sounds like you have at least three separate problems ... the power failures, DSC light, and misfires.

 

Thanks so much for the quick reply. Here are 3 screenshots of idle, 1500 and 3k (indicated in the screenshot).

Will check into auto zones locally.

 

Ok! Your total fuel trim at:

3000 RPM = 7%
1500 RPM = 7.6%
idle = 18.75

Total fuel trim acceptable range is -10% to 10% with zero being perfect.

Now what does all this fuel trim mumbo jumbo mean? Positive numbers mean the engine is running lean and the computer is calling for more fuel and it's driving the fuel injectors to be open for a longer period of time. Negative numbers mean the engine is running rich and the computer is calling to pull fuel away.

Base on the numbers you presented, I would imagine your misfire is occurring around idle RPM, and the first thing I would look for is a vacuum leak. I don't suspect the fuel pump low pressure situation because your fuel trim numbers look good at the higher RPM.

Is the misfire code still in memory or did you clear the DTC? If the P0300 is still in memory, post the freeze frame data. Also post your upstream O2 sensor graph; take a snap shot when the engine is running at 2000 RPM and the engine is at operating temp.

 

I also just notice your intake manifold pressure doesn't look right.

at 3000 you have 38 kPa
at 1500 you have 32 kPa
at idle it jumps to 44 kPa (it should be lower than the 32 kPa you had at 1500 RPM because at lower RPM there's more engine vacuum). This makes sense when combined with your fuel trim numbers as the higher 44 kPa number at idle is telling the computer there is more air flow than their actually is, so the computer asks for more fuel to get to the correct fuel/air ratio.

You may have a MAP sensor that's lying. Shoot me your VIN so I can look up your schematic.

 

I can’t be sure because I never pay attention to this normally, but it feels that something does feel off at higher RPM (too?). I say this because I have a crackly exhaust (Borla sport) and it usually crackles when I let off the accelerator, but it feels like it’s crackling a little when I’m revving a little and not letting off the accelerator. It may do that normally but I’m not 100% sure.

And here is the data you requested, I hope. I wasn’t sure which O2 sensor graph you wanted, but it seems Bank 1 Sensor 1 is what is relevant here? I captured % and V. Note- I’m not sure I did this right, the graph fluctuated a bit as I revved to 2k and tried to keep it there.

again, really appreciate your help on this!!

 

Well, it looks like your B1S1 O2 is switching, but it's switching slowly. You should see 1-5 cycles per second, and I'm seeing 1 cycle in 5 seconds. How many miles are on that O2 sensor? This could be a problem with the sensor or your tool depending on its sampling rate. Need your VIN.

 

Ok, I got your VIN ... same '06 MCS as mine. It does look like you have a faulty MAP sensor based on the numbers you posted. I see you haven't cleared your codes yet. Post your freeze frame data.

 

sorry forgot to add that screenshot too!

 

From the freeze frame data you can see that you're off the throttle with a throttle position of 16.07%, rpm at 1220, but your manifold pressure is 67 kPa (that's almost 10 pounds of boost). There's no way your supercharger is producing 10 lbs of boost at 1220 RPM. Looks like your intake manifold pressure sensor is stuck.

 

1) when all is said and done, let me buy you a beer or something (can figure out logistics later)
2) I don’t fully understand the difference between the MAP and TMAP sensors, is this one of those? And is intake/inlet referencing the same here?

 

2. Map only reports manifold absolute pressure; TMAP reports intake temperature too. Your sensor is a TMAP. It's bolted on the intake manifold just below the intercooler. Some manufacturers use MAP and boost pressure sensor interchangeably. Not all engines have forced induction, but many normally asperated engines have MAP sensors.

 

Thanks! Im trying to identify the right part. Is intake manifold, inlet manifold, intake/inlet map sensor, are these all referring to the same/right part?

 

Here's the part number.

12140872679

 

Fortunately the car was able to get me back home even with the code and Service Engine Soon light on. Now time to repair!
One question- In looking at some sellers/vendors, I see the sensor listed under the part number you provided, but it often doesn't say TMAP, e.g:
https://www.europaparts.com/manifold...140872679.html or

Any idea what this means?

Thanks again for your help!

 

According to the FCPEuro website; NTK is the OEM supplier for this sensor. However, they are backordered at FCPEuro.

You can get it at Rock Auto. Don't worry about the nomenclature; the part number matches.

https://www.rockauto.com/en/partsear...um=12140872679

 

Great. And while I'm placing the order, you don't believe there is any indication it could also be the MAP sensor and I might want to pick one up in case? Or just TMAP?

 

What a great bunch of guys on this forum!

 

If I'm not mistaken the car uses either one or the other, not both? Is this correct?

 

Temperature and pressure are combined into one sensor.

 

I’m saying some cars have a tmap which is temp and map combined and some cars have just a map sensor, is this correct?

 

You would be correct. The justa MINI has a vacuum sensor; the S model has the TMAP. The schematic below applies to all R53 MINIs.

 

They’re all TMAPs. The R53 uses the R50 TMAP as just a MAP sensor. Same part number and everything. Not sure why it calls the R50 part just a vacuum sensor despite even having the temp sensor symbol in that diagram.

To be clear, the R53 has a second TMAP after the supercharger in addition to the TMAP that doesn’t report temperature (“MAP sensor”) to the DME (note how pin 2 on the rightmost component in that diagram is missing).

 

New TMAP installed!
I cleared all codes, drove a little, and the DSC went on again, no service engine soon light though, so no codes or freeze frames to show at this time.

And as you requested, same screenshots as last time with the new TMAP installed.

Thanks again!!

 

Your total fuel trim (TFT) went from over 18 at idle to 1.57, Excellent! The part that has me curious is your manifold pressure at idle (old sensor) was 44 kPa; your new one is 45 kPa. I expected to see that drop significantly. I'll have to plug into my MINI today to see my numbers and compare. The DME will adjust fuel trims as it adjusts to the new TMAP sensor.