Help diagnosing a P1320 2000 Q45

[Skoat]

So I am looking for any input on an issue with my brothers 2000 Q45. Long story short, We just replaced the cam cover gaskets (as well as Plenum and EGR gaskets), all 8 spark plugs and ignition coils and on the second start of the car, it threw a SES, TCS off and Slip light. Vehicle runs wonderfully, drives and shifts fine, but sets the lights. Scanned it after work today and was greeted with a P1105 and P1320. The P1105 went away after clearing the codes (as a starting point) and hasn't been back so not worried about that right now. The P1320 however is a hard set code after the second start of the vehicle after clearing. I have an Infiniti Service manual for this car, so I have been going over the diagnostic tree for this code. So far all I have done is verify that none of the wiring at any of the ignition coil connectors is nicked or broken, and I have pulled the new coils out and OHM tested them based on the Service Manual component check. This is where I am looking for input. The Service Manual states that as long as the OHM reading on terminals 2 and 3 of the coil reads more than 0 ohm or OL, it should be fine. 7 of the coils range from 10.11-10.30k ohm (they were mildly warm due to the engine running about 2 hrs earlier), but one reads at 11.71k ohm. Now, these are Ultra Power coils from Rock Auto so I know quality can be spotty, but I am wondering if this is messing with the control from the ECU given the higher resistance (by about 1k ohm) or if I should start looking at issues with the Camshaft Position Sensor as it was in the area of oil leaks and brake clean spray.
(I have about 7 yrs doing diag on GM's so not afraid to get into the nitty gritty, but I am limited in my knowledge of not only other makes, but older cars in general.)

Any help is appreciated. Really wanna get this back on the road for my brother.

[VStar650CL]

P1320 is always either a defective coil, wrong coils, or wrong spark plugs. Nissan ECM's from the early days of the changeover from distributor to COP were very fussy about coils, so China-cheap ones are usually a mistake.

[VStar650CL]

PS - Ohming coils which have a built-in power transistor is usually a vain exercise. You can tell if the secondary side (the winding which connects to the plug) has a problem, but the body diode characteristics of the driver MOSFET's vary so much from manufacturer to manufacturer that ohming the primary tells you nothing except that the FET isn't blown open-circuit or melted short. It's completely useless as a measure of coil performance.

[Skoat]

PS - Ohming coils which have a built-in power transistor is usually a vain exercise. You can tell if the secondary side (the winding which connects to the plug) has a problem, but the body diode characteristics of the driver MOSFET's vary so much from manufacturer to manufacturer that ohming the primary tells you nothing except that the FET isn't blown open-circuit or melted short. It's completely useless as a measure of coil performance.

I had a pretty good suspicion that that was the case. Just the only procedure that I felt like carrying out at 8pm other than the wiring check. Is there any way to try and figure out which coil could be causing the issue? I have read elsewhere that we should probably replace all with Hitachi's but I'm not sure he is gonna be willing to spend the extra $350 for a full set.

[VStar650CL]

If you still have any of the original coils and they weren't throwing codes, try replacing the new ones one by one with one of the originals. If you hit one cylinder where the code stays clear, that's the culprit. If you run through all of them and the code is still popping up, then you know that coil brand is crap and won't work.

[Skoat]

If you still have any of the original coils and they weren't throwing codes, try replacing the new ones one by one with one of the originals. If you hit one cylinder where the code stays clear, that's the culprit. If you run through all of them and the code is still popping up, then you know that coil brand is crap and won't work.

If only I hadn't thrown them out ah well, I appreciate the help. I'll look into getting new Hitachi coils for him.

[98_Q45]

Before buying all new hitachi coils, I think there’s a way to isolate which cylinder is giving the misfire. However in my Nissan Maxima, it was giving a p303 code for a long time, with a blinking check engine light and poor fuel mileage. I replaced all the coils with knock offs, but then that one cylinder 3, I made one last ditch effort using hitachi (after spending $140 at the dealer only to be told, “This model Nissan doesn’t like non-OEM coils” and the problem went away. However, the check engine light still has a code for the ignition signal or something for that harness: but it’s not blinking and the fuel mileage is good now, so I said f*** it. Mind you, all the other coils are $10 knockoffs except that one

So changing coils with OEM may or may not work. It could be down to wiring harness, which I’m finding again and again: some like MAF, alternator, and intake air connectors get brittle and break.

In the Q however, I also have knockoffs and they work fine. No codes or misfires. But I did change them a 2nd time due to a mystery issue I’m dealing with. But that didn’t make any difference.