Question about BMW Z3
P0301 is a misfire on number one cylinder that is the rough running, as to what the source of that is will require a thorough diagnosis, it is not cut and dry and it can be a multitude of things causing the miss, start with the ignition system, poss causes are in order of how common it is
1. Defective spark plug
2. Defective ignition coil for #1 cylinder
3. Intake manifold vacuum
4. Defective fuel injector cylinder #1
5..Defective #1 fuel injector driver circuit of Powertrain control module
6.. Engine mechanical problems, low compression due to scoured cylinder or burnt valve or flat cam shaft lobe etc..
Fuel trim lean, the unburned fuel from #1 cylinder misfire going out the exhaust is causing this problem I think, but it could be be the MAF (mass airflow sensor) sensor, I suggest u isolate the problem with the #1 cylinder and repair it then clear the codes and drive it, if the light comes back on and the code P170 comes back try cleaning the MAF sensor, many times that cures the problem.
Posted on Apr 29, 2010
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
Tips for a great answer:
Nov 20, 2016 | BMW 128i Cars & Trucks
Nov 30, 2017 | 2000 Isuzu Rodeo
Dec 05, 2009 | 1999 BMW Z3
Oct 06, 2009 | 2009 BMW 5 Series
Jul 19, 2009 | 2000 GMC Sierra
Jun 29, 2009 | 2000 BMW 3 Series
Mar 17, 2009 | 2000 Chevrolet Venture
161 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: