Multiple Bank One Misfires

Good afternoon, my question is with regard to my 1999 C2 manual with 81k miles. Check engine light came on and used my generic code reader which reflected codes P0300, P0301, P0302, P0303, P1319, P1313, P1314, and P01315. The P0300 series is random bank one multiple misfires, and the P1319 series is bank one emissions related misfires. So, I began by looking at the bank one (cylinders 1, 2 & 3) coils, plugs, injector ground wires, and O2 sensor wires. In looking at the injector ground wires where they attach to the cylinder head, I noticed an electrical plug dangling loose by where the crank position sensor wire comes through a plastic clip. This dangling electrical plug appears to be the female end of a connection with provision for two male prongs (as opposed to the smaller pins). This plug has two wires coming out of the back, one is violet and orange, and the other is light blue and orange. This plug also has a metal retaining clip around the exterior. As usual, this plug is in a super tight recessed spot and I was unable to get a decent picture of it, couldn't even get an extension mirror in there. Can anyone offer any guidance as to what this plug is and where it goes? I highly suspect it is the source of my multiple bank one misfires. The crank position sensor plugs, cam position sensor plugs and fuel injector ground wires are all in place and firmly seated/grounded so I know its not associated with any of those. Thanking you all in advance for any help you can offer.

I assume u have a manual because i think that plug is the imfomious extra tiptronic plug. These kind if misfires can really make u chase your tail. It can be vacuum leaks, bad sensors (maf and o2), coils or plugs, issues with the variocam system, grounds or even the dme. U need to get a good scanner on it and learn how to read the telemetry or u will just me throwing money and parts at it and get fustrated.

De Jeeper, thanks for the prompt reply, as Monty Python would have said, no one expects the Spanish Inquisition, I mean the extra tiptronic plug! I do indeed have a manual as mentioned in my original post. I guess that after 9 years of ownership it's time to invest in a Durametric scanner. My son in-law has my former 1999 Boxster, so it will be worth it to support both cars. My 996 is recently recovered from a cracked cylinder head during which I changed the plugs, plug tubes, coils, fuel filter, AOS, O2 sensors and coolant reservoir tank, although I acknowledge some of those electrical parts might be bad right out of the box. Car has been driven less than 500 miles since due to a recently revived Harley Davidson jones, and had been running sweet. This most recent Check Engine Light episode began a couple of weeks ago on my way to the NJ State inspection station, check engine light popped on literally down the street from the inspection station. Scanned the codes and got P0452 and P0506, subsequently changed out the Fuel Tank Pressure Sensor and Idle Air Control Valve. Those codes disappeared, however, that's when I started getting P0300 and P0319 series codes so, yeah, I've already thrown a few parts at it. Again, thanks for the prompt reply.

Honestly since u were working in the area i would investigate the maf senor first. It can cause so many ramdom issues all over our cars. to make things worse some have reported going through 3 bosch oem sensors before spending the $ for a factory branded sensor to solving their issue.

I hear what you are saying about the MAF, its probably the original and 23 years old. I actually cleaned it with some CRC MAF cleaner, but here's the thing, all of the misfires are on bank one and I suspect that if the MAF were indeed the culprit, the misfires would appear on bank two as well, no? As all the misfires are on bank one, that's where I've focused my attention. Today I pulled the bank one plugs, coils and Crank Position Sensor which was a major PIA as the aluminum oxidation kept it locked in its hole and its in a super tight spot. I actually undid the motor mounts and lowered the engine as much as possible to get some level of access. I also wanted to get a better look at the AOS plumbing and everything looked good, but the accordion boot looks a little wet with oil residue. Both clamps are in place and tight, and the AOS is bolted tight to the block, so I suspect the oil is coming from the crossover tube which resides just above. Also, I checked out the Durametric and the price was doable ($289), but I don't own a lap top, never have. So to get a Durametric I would first need to buy a lap top which probably triples the price of the whole endeavor, we shall see.