P1424 Mass Air Flow Error Code

Phil-E30 · Post by **Phil-E30** » Thu Jan 05, 2017 5:37 pm

Afternoon all,

Had an EML come on today, throwing up a code I have seen before P1424, pointing to an error in the Mass Air Flow system.

I have had this code appear intermittently on the car, I replaced the MAF (albeit with a second hand part, but this was from a forum member who knew it was working). This leads me to suspect another culprit in the MAF system.

Going to give the MAF sensor and terminal a bit of a clean as a starting point, but also aware that there could be vacuum leak or such like. Anybody aware of any repeat offenders I should be looking out for or any key hoses I ought to be checking?

Much appreciated, as always.

Phil

Chris_D · Post by **Chris_D** » Thu Jan 05, 2017 5:40 pm

If memory serves, that was one of the codes mine was throwing when i bought it.
I replaced the intake boot between maf and intake manifold, cleaned (carefully with lekky contact spray, not carb cleaner) the maf and the code's never been back.
def check for holy hoses!
good luck

Phil-E30 · Post by **Phil-E30** » Thu Jan 05, 2017 5:52 pm

Cheers Chris. Have a few bits and pieces planned, so will incorporate this. Just wondered if there was anything common or more likely to be the culprit.

Chris_D · Post by **Chris_D** » Thu Jan 05, 2017 6:03 pm

Phil-E30 wrote:Cheers Chris. Have a few bits and pieces planned, so will incorporate this. Just wondered if there was anything common or more likely to be the culprit.

wwell, they were my thoughts too at the time.
unfortunately i'll never know if mine was a dirty maf or holy intake boot as i addressed them at the same time.
i also had to replace the throttle body and i gave the ICV thoroughly good clean out too. so couldve been any, all or a combination of things really.

Phil-E30 · Post by **Phil-E30** » Thu Jan 05, 2017 6:04 pm

Interestingly, this resource http://www.bimmerboard.com/forums/posts/517875

Suggests that P1424 is actually 'P1424 - Bank1, Secondary Air System Leak Detected', not sure why this is different to other resources.

Which is interesting as I also recently got a code P0492 - Secondary Air Injection System; Insufficient flow bank 2.

Are these codes linked then? And does that mean the MAF system isn't the issue?

Phil-E30 · Post by **Phil-E30** » Fri Jan 06, 2017 6:31 pm

Anyone have any thoughts on the above?

andyfanshawe · Post by **andyfanshawe** » Fri Jan 06, 2017 8:19 pm

Phil-E30 wrote:Anyone have any thoughts on the above?

This is where equipment comes in handy.
Few options here.
If you can get access to live data, look at short term and long term fuel trims AT IDLE.. Add them both together and it should be between -10 and +10. Short term may be changing fast, but shouldn't get more than + or - 10.

Now raise the engine speed to 2500 ish. Again, they should be between + and - 10. If they are out of range at idle, but improve at 2500, this is a sure fire indication of a vacuum leak. Better at 2500 means it could be a faulty MAF or dirty MAF.

Another option is to get a squeegy bottle with water in. get the engine to idle and spray the entire induction system down. And don't hold back! You will hear the water being sucked in if you find a vacuum leak. Don't worry, it wont harm anything.

Next option is to get the voltage at the signal cable at the MAF. Snap rev the engine and take a note of the highest reading. A scope is perfect for this. IIRC, we are looking for 4.1 volts or higher. Checking for good powers and grounds at the sensor is essential.

Not easy for DIY here. A good level of equipment and knowledge and wiring diagrams is key.

Andy.

Das882 · Post by **Das882** » Fri Jan 06, 2017 11:28 pm

Don't know if you have seen my post at the end of last year.....I got the same code as I slowed down to 40 on the motorway as I hit a patch of freezing fog. I stopped and checked and found everything was normal and carried on home, I plugged in my code reader and cleared the fault and took it for a spin the next day with no problems. Maybe it is coincidence but I'm sure it was the sudden temperature change of maybe moisture???? Out of interest what was the wether condition when it happened to you?
Dave.

Argenta · Post by **Argenta** » Sat Jan 07, 2017 4:39 am

What airfilter do you have?

Das882 · Post by **Das882** » Sat Jan 07, 2017 9:09 pm

Argenta. If the question is for me it is a K&N reusable.
Dave.

Argenta · Post by **Argenta** » Sun Jan 08, 2017 5:32 am

Yes so I thought, that sort of code seems to be a reocurring thing on all cars with that type of air-filter. Evil stuff

Das882 · Post by **Das882** » Sun Jan 08, 2017 7:23 am

That's interesting, hopefully it won't be a reoccurring problem? as it was a one off driving the car at that time of year,

goon · Post by **goon** » Sun Jan 08, 2017 11:10 am

Had something similar on my car few years back, garage did a smoke test on it and found a pinhole in the small 90 deg rubber hose at the back of the air intake. Worth checking maybe.

Das882 · Post by **Das882** » Sun Jan 08, 2017 1:24 pm

Thanks for the heads up I'll check and see if mine is ok.
Dave.

Phil-E30 · Post by **Phil-E30** » Tue Jan 10, 2017 3:04 pm

Thanks for the replies on this guys.

Due to work and travel, I've not been able to get a look at this yet. I will post results once I get a look!

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