97 Boxster Misfire 1 bank
 

Just purchased 97 Boxster , vehicle parked for a long time , starts good , idles and runs good .

The problem appears when accelerate fast , the engine looses power , misfires
When accelerate slow - no problems.
CEL went on and flashing.

Misfire codes detected:

P0300: Random/Multiple Cylinder Misfire Detected
P0301: Cylinder 1 Misfire Detected
P0302: Cylinder 2 Misfire Detected
P0303: Cylinder 3 Misfire Detected

Spark plugs replaced , fuel filter replaced , MAF sensor cleaned

It got a little bit better after cleaning MAF sensor , CEL doesn't come anymore , but the problem still exist

Any ideas?

Welcome to the club!
How many miles?

Only 85.000 KM

I'd be checking the MAF specifically and the induction generally for airleaks.

Take the engine cover off, check for leaks, broken clips, etc. If nothing obvious, unplug the MAF and take it for a run. If it makes no difference, that will eliminate both leaks and MAF from the equation.

Disconnected MAF , took it for run , much , much better , almost perfect.
Obviously MAF needs to be replaced , what would be your suggestion , OEM or replacement? Very big price difference...

I find it odd that the problem occurs on only one bank since the MAF measures airflow before it splits off.

0.280.217.007 is the Bosch part.

– contaminated, faulty or wrong spark plugs
– Contact resistance
– Loose connections

More info here

You need to be sure the MAF is faulty rather than that the problem is an air leak between the MAF and the engine (air leaks above the MAF will not cause this problem, but still need to be attended to as they'll be letting dirty air into the engine).

You need to check the hoses and clips between the MAF and the engine. If you're sure there's no leak, I would bite the bullet and buy an OEM MAF. It should last a good few years so long as you keep your air filters in good shape.

A have an update.
Still waiting for a MAF sensor shipped
Today , after disconnecting the battery for 30-40 min loss of power and missfires appeared again , CEL came on , codes were Missfire Cyl. 4,5,6
I took a MAF sensor a part , cleaned it again , the problem gone.
Can MAF sensor cause missfires first in Cyl. 1,2,3 and then 4,5,6 ?

No visible air leaks found

Sorry for bumping!

I have the same symptomps and error codes, except i get no significant improvement when disconnecting or cleaning the MAF. More ideas? What hapened to you m12volt? Updates?

just had this problem. I had a major exhaust leak between the headers and cat so it was throwing off the O2 sensor. I had a misfire on 1,2,3. At first it got better when the car warmed up. I have headers, and an aftermarket exhaust so I didn't notice it, the car is loud as it is. Hope this helps.

Cheers.