Dynasty47x1

This is a long story and i have been having the problem since July. One of my coilpacks went bad and fried my ecu and engine harness so my car started misfiring the cost to fix was 3600. I got that fixed car was running fine. then a month and a half later it starts misfiring again at the time of the first repair they replaced 1 coil i take it back in and the coil they replaced went bad so it was replaced under warranty. Everything is going good then twp months again it starts misfiring this time it was 1 sparkplug the plugs havent been in the car for a year and they are ngk 17 for that good again. Starts misfiring again same coil they replaced replaced the coil again and for the hell of it had all new coils put in everything good but all this time the misfiring is on and off.
Just took it in again for misfiring i went on a Saturday and the rep at Nissan (who knows me by name now) tells me to comeback in on Monday cause one of the best Nissan techs will be in. I take it in Monday i try to wait it out cause im tired of rental cars but i have to get 1 any way. I call to check up on the car and they don't know what the problem is they're contacting Nissan for help. i get the car back Thursday. I had put a grounding kit in since the last visit so the only option they came up with was oh the grounds where a little dirty so we cleaned them and the car is running fine thats all they did supposedly. Yeah the car was running fine (oh I forgot the car is misfiring while the CEL is off) now its starting again on and off and the CEL is back on. I think my cat is bad also because when im on the highway the car will drop power then pick it up and the drop again and my car just smells like a gas station guess the thats the running rich maybe. And before when the car was misfiring I couldn't go past 3k before without the CEL flashing. Now the misfire is under 3k since its intermittent its drivable to clear the misfire i have to go above 3k for the car to run somewhat normal. Im tight i dont know what to do and i dont want to get rid of the car and i dont want to make payments the car is paid does anyone have any idea of what to do im going to head out to Nissan in a few hours. Could the Cat be causing this problem

qnpark8282

iTrader: (2)

I had the same exact issues. No cel so code P0300 muliple misfire. Car drives some what fine. Has power sometimes and sometimes it dont. Replaced all 6 coils, while replacing noticed that my valve cover had a huge leak. puddle of oil when i pulled my coilpack out. Replaced all 6 injectors. Replaced the maf. Your random misfiring might be your injectors.

Dynasty47x1

I replaced the maf where you able to get it under control? im getting ready to head out to nissan. im thinking it has something to do with the gas cause its also like when i get down to a quater tank when it starts acting up the worse and i use premium.

Scottwax

iTrader: (8)

I had a similar problem with a Honda that turned out to be worn insulation on the wires to the O2 sensor that would ground on acceleration and over bumps. Took forever to find the problem too. It might be something similar, a wiring problem that is messing up the coil packs.

Dynasty47x1

Well i just got back from Nissan There's no techs to check out the problem have to wait till Wed, but until then for my Christmas present im having the Cat replaced today since it is clogged and breaking up. Which o2 sensor do you think would be causing the issue all of mine proably need to be replaced 337 to replace the cat. I had a list of things that needed to be replaced but I misplaced it.

mastere954

iTrader: (17)

i had very similar problem for about 4 months, i kept taking it back to nissanand they told me i had a code for a crank sensor.they kept insisting that the crank sensor had nothing to do with the problem and that it would not cause a misfire. so the replaced my MAF, nothing, still misfiring at in between 3k-4k rpm. replaced the coil packs, still misfiringi told them i had a gut feeling about the crank sensor being the problem and they kept denying it. i got pissed and made them change the crank sensor, car runs perfect, not the slightest misfire. check maybe for a crank sensor code, i've seen this issue with the cranck sensor several times

Dynasty47x1

I might ask the shop thats doing my cat to pull the codes but theyll proably charge me for it even though they're working on my car ill go to advance and get a print out.