p0303 cylinder 3 misfire, Need All the help I can get PLEASE

[romanfishin]

OK starting this new thread in hopes of getting all the help I can get, from my last thread it got backed up a few pages.

I am getting a p0303 cylinder 3 misfire only code, I started getting this I believe after I changed the ccv with the p0173, p0170, p1188, p1189 which went away after the ccv repair, unless that po303 never got detected because those other codes were triggered.

I have swapped coils and boots at least 3 times from different cylinders, spark plugs changed and swapped. Fuel injectors were supersonic cleaned, flushed and back flushed, with new filters and seals on all 6 injectors tested by Fuel Injector Corp. in Livermore California, They said they all were working perfectly all flowed exactly the same. Just Did a new oil filter and Mobil 1 10-30 advanced fully synthetic oil with OEM MANN filter. Did compression tests and all cylinders were between 200psi and 205psi. Also reseated the connections from O2 sensors, injectors, coils, grounding etc.. Also all 4 O2 sensors are new OEM Bosch

Could a bad MAF, DISA valve, ICV, Valve cover gasket, or Vanos seals (throwing timing off) cause a misfire only on one cylinder misfire like #3?? or can that code be triggered from a different cylinder problem be it the coil, plug, etc..

I need to fix this freaking problem so I can clear the engine light and take it in for emissions test. I am afraid to take it to dealer or shop because they won't guarantee that what ever they say will fix it. Don't wont to throw money on unnecessary parts.

Anyone have had or heard of a single misfire code or even had this p0303 cylinder 3 misfire code?

Need your Help please, Thanks to everyone who has helped me so far.

I have a 99 528i 52TU engine with 218,000 on it. Rough Idle only when code is on, runs smooth every time I clear it.

If I post the Live Data from my scanner would that help? Not sure on the ranges of all the things in the Live Data..

Thanks.

[Gumbi4u]

Try to keep everything in one thread. No need to start another. All you are doing is cluttering up our forum.

In any case, swap the injector with another cylinder for good measure. Also make sure your o2 sensor connections are tight and not swapped around.

[romanfishin]

Thanks, the thread had a different subject that maybe keeping people away. Anyway I swap the injector and still stayed on 3, the plugs are seated tightly also. Not sure what else to do.


Come on guys I'm sure someone had this problem or similar one like this. Please help.

[russiamutha]

bump, same issue...

[edjack]

Have you determined that the injector is getting the signal? There could be a wiring or output stage malfunction.

Can you feel/hear the injector buzzing?

[Poolman]

Electrical connection for the injector--or maybe a vacuum leak going to that cylinder--my best noodles