Hey guys,

I'm really hoping someone could help me diagnose this problem. I was driving to work one day and was going 80mph, all of a sudden the car just jerked and felt like it was losing power, the CEL was blinking and that was it. Hard to get RPMs up. I decided to take it to work since I was halfway there which was 15 miles. I then limped it back home going 40mph for another 27 miles, dumb, I know, but the car isn't brand new. I researched the forum and decided to change the crank sensor because it was rough idling and I can hear the clickings/knocks as I was taking it home. the OBD said it was P0300 and P0305.

Researched some more and decided to change all my coils and plugs today. 5 was burnt out and 1 was the only one with significant oil in it. Turned it on and took it for a spin around the block and acceleration was back to normal and so was idling, no clicks or choppiness was noticed. I decided to floor it for a bit just to test and the CEL started flashing again, damn it. I eased off and took it home and then it went away. Now I'm confused. I just want this car to last me another year before we part ways, not trying to put too much money into rebuilding either. I know I probably need valve cover gaskets, but what is still causing the misfire? I checked the MAF and that's clean and fine, could it be clogged CATs? I'm not too sure about it because a P0300 is like 8 different issues.

If anyone can help a guy out fix this issue, I'd be forever grateful.

 

Did you scan it again to see if it was throwing any other codes after that second drive?

As for the crank sensor, probably not your issue since it wasn't throwing a code for it, if you replaced it with anything other than the Genuine Nissan OEM or Hitachi (the OEM supplier) sensor then you may have created another problem since these engines are notorious for not working properly with ANY aftermarket sensors.

Since it wasn't throwing any code for the CKP sensor I would put the original one back in unless you did use a HItachi or OEM one.

 

well, I guess I goofed and didn’t do an ecu reset after the new plugs, but I did do it several times while I was waiting for the parts and tinkering to see if anything changes. I’ll erase the codes on the reader and take it for a drive today around the block, but the only code that showed was P0300, before it was 300 and 305, the coil on #5 was burnt. As far as the crank sensor, it’s not OEM, but it did help get my acceleration back up, this car was struggling to get past 2.5k rpm and it took like 1/4 of my tank to drive 25 miles.

Would it be possible that excessive gas is leftover in the cylinders? After I took it home, didn’t drive it at all until I got my plugs and coils installed yesterday. I’ll double check the maf and intake installation, I heard that may be an issue and topping off the oil with a bit more than the 5qt I did.

 

Don't go over the high mark on the dipstick.

You can reset the ECM fuel trim by disconnecting the battery, pump the brakes a few times to drain residual, wait 10 min, hook battery back up. Or you can pedal dance the reset.

If the coil was showing physical damage you should consider replacing the ignition condenser which might also be fried and the reason why the coil cooked off. It's taped to the coil pack harness at the back of the engine and it's about a $10 part.

Here's a link to the pedal dance, use a timer the seconds counts need to be exact.

https://www.nicoclub.com/archives/g3...procedure.html