UPDATE:
I removed my CAT and I saw a little better response at idle, but when I drove my car, it still was acting up, though not as bad. I think that the CAT is symptom of the problem. There is something else effected the car, and I just can't nail it down.

Man this sucks!!!

 

yeah man my rough idle is annoying too.. i'm just happy to have my power back.. but i'm wondering if i'm still missing any power because of whatever's causing the rough idle???

 

I really want to get headers or stab the ish outta my cats regardless. Ridding of my P0300 would be a bonus.

 

Okay my p0300 is finally gone. It was the plugs, They weren't gaped right.

 

neither were mine.. that didnt fix my problem though.. what kind of plugs did you get, what were they gapped at originally, and what did you set them to?

good stuff though! 2 P0300's gone so far... zero2sixtyZ you're next! if it bothers you that much, you might wanna think about investing $100 in a nissan diagnostic for their machine to tell you exactly where it's coming from... OR... go to a deal, talk to one of the techs, and see if you can slide him $20 or so just to scan the computer for you

 

I've got the NGK plats. Im not sure what they were gapped at.. But i gapped them to .44

 

hmmm... i'll check my plugs again. i bought OEM when mine were done around 20,000 miles ago.

 

okay nvm. Freakin code came back this morning.

 

Do you have any rattling in the front timing chain cover? I had the same code in my 96 max it was a headache turned out to be the timing chain guide/ tensioner caused the problem the rattle wasnt loud only at 1500 rpms, to much slack on the chain causes the timing to be off a little bit. Also Bad tensioner caused slight knocking until the motor reached operating temp.

 

Have you guys tried replacing ckps(ref)or(pos) I know you guys are not reciving a cel from it but its worth a try imo.

And the whole knock sensor thing the 4th gens use a 470k resistor in the ks harness wouldnt hurt to try only 99 cents at radio shack. also iirc when replacing a ks you have to drive it around for some time before the timing goes back to normal

also i know there have been 4th gens that have had issues with plats and other high end plugs. ever think about putting coppers in and give it a try??

 

any update?

 

mine popped up today =( ... wuts the soultion to this?

 

well i took out my 3 spark plugs closest to the radiator(i wasnt takin off my intake mani to get to the other 3) i wiped them down(cleaned the thread a lil) put them back in...before i put the coils back on i put spark plug grease(or w.e its called) and put it inside the coil jus a dab...and some ontop of the spark plug itself...deleted the code...started the car and no code poped up so far...drove it all day...just a idea for you guys...it will prolly pop back on 2 morrow lol....ill see wut ahppens

 

i finally got around to changing the plugs, and while i was at it, replaced the coil packs. no more cel! things seem to be smoother than before; mpg is a hell of a lot better, but i have noticed a sputter or a gurgle in the exhaust when i lay off the gas and coast. and so it goes...

 

i greased my spark plugs lik i sed 2 posts up...no cel in 2 days and everything is good...didnt even change my plugs either

 

My $.02.

I've been experiencing power also, as you all have. After searching and reading so many threads, I thought I'd give the KS Simulator a chance.

After consulting the manual, I went to Radioshack to grab a resistor between 500k-600k. They didn't have one so combined two resistors to make a 550k value.

Inserted it in the the KS harness going towards the ECU, reset the ECU, then went for a drive.

Verdict: It pulls better than it has in a long, long while. I'm assuming the KS is on its way out and not providing a correct resistance to the ECU.

 

I went to advanced autoparts and they told me i have multiple misfire as well. But, i got the code about a month ago and it went away in less then a day, got it back yesterday and drove it around this morning and again it went away. So idk, could it be the coils or spark plugs or could it be something else? I don't think it's the coils or sparkplugs because if the code keeps going away i don't think the plugs and coils get good again.

Is there anyway to get the exact diagnosis from a shop or dealership??

 

Update: i brought max to a friends garage and he ran my p0300 code...came up as crankshaft position sensor. so my next step is to locate those and clean them. if that doesnt work im going to buy new ones.
sidenote - i ordered grey and pink dots from daveb and he sent me reg ones so make sure your super specific.

also I reset my ecu and it passed immitions(or however u spell it) for my inspection sticker

 

yeah, you need to either go to a nissan dealer, or a shop that has a nissan consult 2 to tell you exactly where the multi-cylinder misfire is coming from.. my suggestion is to go to a dear, talk to a tech and see if you can slide him about $20 or so to scan the computer for you instead of paying $100 at the service desk

 

Scanner can tell the cylinder only if the car ECM has stored the cylinder specific code. Does anybody know for sure if Nissan Consult tool can tell the cylinder number without cylinder specific code present?

- Vikas

 

yeah it can... i had a P0300 (random cylinder misfire) code.. when i took it to nissan, it narrowed the misfire down to cylinder #2

 

there is a TSB for maf sensor replacement and/or ecm reprogramming for a hesitation between 2k-3k if your ECM part number falls under a certain range.

also the 5.5gen maxes are known for the spark plug gaskets (on the rear valve cover) to leak oil into the spark plug cylinders which will cause a p0300. it will eventually foul out the coilpacks on bank 1 . the ECM throws a p0300 code because it cannot determine which is misfiring.

chris, i don't think i've met you personally but we're on the same team lol. martin ( white 5.5 with 3" catback) is also having a p0300. i have narrowed it down to cylinder #2 coil pack dead and possibly the neighboring ones on its way out. i'm a tech at montgomeryville nissan if you need help or a quick scan, let me know.

 

hi, am new here am very much interested in owing , having a repair workshop in my area , i live in africa a lot of cars were abandoned becouse people have no idea.
i think i can cos i have the opportunity and ability

regards
Chike

 

hmm, thats itnteresting because my car just developed that hesiation, and a VERY slow pull from 4k up to redline

 

Do you happen to know the ECM part number range so I can see if this applies to my '03? Thanks.

 

I have the same code on my 04. Could it be the ECM?

 

Just my car checked out. It has the p0300 code that comes and goes. They replaced all the sparks plug due to them being worn down (car has 77,000 miles), cylinder #5 was full of oil and the coils was swollen so they replaced that coil. Didn't have valve covers in stock to replace them so everything was cleaned up and covers ordered. Right now car is running perfect. I think these crappy valve covers are the cause of most of the coil issues by allowing the oil to leak inside....

 

i've been getting p0300 from time to time too but i have no oil leaks nowhere, replaced all of my plugs today and the code came back lol, will be dropping the car off at dealer on tuesday if i know wny results i'll post.

BTW i also have midrange power loss if i give more than 30% gas, past 4k it runs the way it should

 

soo nobody has figured this out yet? I have been dealing with this almost a year now. and having an exhaust it sux because the missfire is so loud This past friday we did the 6th gen valve covers and new sprak plugs. started it up and still the same thing. and like always, half my commute to my destination its running okay. id think the oil will dry out over time?? iduno, im gonna try the 02 sensors next.

 

i have appointment with teh dealer today @ 3pm i hope to get results. will post after

after i replaced rear plugs on weekend and car seems to run better even though they were perfect. maybe she just wanted to be molested by me lol(taking off the manifold) code came back right after i started her up

 

my cam sensor caused my multiple misfire code for months...the cam code never came up in the computer for months till 1 day it came as a pending code...fixed it...no p0300 ever since

 

i came back from the dealer after 2+ hours there, 2 mechanics working on it, one was GTR certified, all they could figure out was that my A/F ration was off and messed up idle speed. i think they liked the puzzle, here are the printouts i asked for.
code did not come back as of yet, we'll have to wait and see, car seems to drive and idle better.

 

any update?? it came back up and bin comin back alot latly and nothing is wrong with my car

 

i dont have code anymore but car is still slow. i'm as fast a C230 compressor :'(

 

^^ wt was the fix tho

 

This is a PITA. I've had it for a long time now. Had all the plugs changed and the SES light reset and it came back on after a week or so. It comes on and goes off randomly. Low power, hesitation, choppy idle and what seems to be low idle (600rpm).

I'm thinking the catalytic converter could be a cause but I don't know. It's somewhat distressing to see all the rest of you having this same problem and even after you've replaced basically everything, you still have it!

Mine is a little different than yours though. 2003 6-speed with 154000 miles on it. Hoping somebody has an answer.

 

Thought I'd jump into this discussion as well. Why not, sounds like it is a common problem.

I have a 2000, 127K. Same issue: intermittent failure and error code. When it fails it runs like 1 or even 2 are missing. Oddly enough, I've found an "occasional" solution. I pull over (or coast and no not recommended) power off and power back on by starting the motor and BAMB, firing on all 6. If it doesn't work the 1st try then I do it again and it runs smooth. I get the missfiring start and running that way about once a week--but it is random. If I power off I usual can correct it.

I've replaced my spark plugs and MAF.

I've thought it might be the coil packs, but the thought of spending $60 to $80 per pack (X6) to find out it didn't help makes me sick. So I've not tried that solution yet.

 

i have been getting the p0300 code since i did my plugs and intake spacer.

i was tolf the plugs were gapped when i bought them, should i have double checked? fuuuuuuuuuuu.... lol

either way i need to change my rear VC so i will buy all new plugs at the same time. i just dont want to change the coils if i dont need to

best place to order the VC from, and the coils if i need them?

thanks

 

Wow. 3 pages and still nothing on this issue. Anybody have an update?

 

i have a po300 code and i recently had my knock sensor replaced but the mechanic did not put the knock sensor where it was supposed to go, he mounted it on the intake cover or something like that, and my cylinder #5 is completly dead and i have a brand new coil pack and spark plug. any suggestions? also my iac vavle is brand new also, i hav e pretty much replaced every sensor in my car brand new.