[Rpippin]

Hey guys needing some help with figuring out my misfire! Started getting a little misfire 2 months ago replaced plugs it reduced the mis. Gradually it got worse, after driving about 45 min at 80 m.p.h. No engine light came on so i put the truck in neutral turned key off started it back misfire would go away. Yesterday it was misfiring so bad it lost all power and was shaking the hole truck like king kong had ahold of it, couldnt pull itself, but ran fine at idol.Turned it off tried to start back and it took alot of cranks to get it started, when it did,the misfire was terrible. Can someone please guide me on what i should check to fix it. Thanks in advance!

 

[FishnAlaska]

Make sure you reattached all the plugs properly and in proper order, then I would look at replacing the coil packs.

 

[cajun56]

Also have a mechanic hook up scanner and have crank sensor check along with coil packs.

 

[DosLos]

Any updates on this Rpippin? I'm having the EXACT same issue with my 04, 230k miles on it. OBD keeps telling me it's cylinder 4 misfire; replaced coils and plugs, verified that I have good spark at cylinder 4 (shocked the crap out of myself in the process), and just finished testing the injector which looks good. Also did a compression test and that looked fine at around 140psi. I'm at a loss... I did see someone mention issues with the catalytic converter getting clogged up, so I'm gonna check that out next but I have little hope.

 

[nightowl]

Possible clogged primary cats if all the other part listed have been changed. Cats and cracked manifolds are a known issue on these trucks.

 

[DosLos]

UPDATE: FIXED!!

Summary: it was a bad spark plug. Get NGK brand. Bosch sucks (for this truck).

Alright so beyond the diagnostics I listed above, I re-ran the compression test with all plugs off and got between 200 and 210 psi on all cylinders. Also checked exhaust back-pressure to check for the clogged cat of doom that these truck suffer from but it held nice and steady at 0.5 psi. Checked MAF signal and it was within spec, changed out the injector just in case, cleaned the fuel rail, checked signal at the injector while running, and traced out all the pins and cables between the A/F sensor and the ECM. Btw, the service manuals listed here are freaking awesome for troubleshooting: Nissan Titan Factory Service Manuals

After all of this I figured it must be something in the ECM so I took it to the dealer for them to check it out. ECM tested fine but the mechanic was intrigued, so he tested spark and fuel too and it looked good to him. He noticed I had Bosch plugs and on a whim he grabbed an NGK OEM plug he had laying around. Put it in and it was music. No hesitation or anything. He said Nissans are notoriously sensitive to variations in spark plug resistance, and that other manufacturers don't have as tight a spec on that as NGK. Come to think of it, when I checked spark it looked a little purple/orange, not the nice bright blue it should've been. I'm gonna order a full set and change them all out. I hope this helps someone!

 

[KeaneBeane823]

i had the same issue with king kong shaking the truck and it was 2 front cats are clogged

 

[KeaneBeane823]

Possible clogged primary cats if all the other part listed have been changed. Cats and cracked manifolds are a known issue on these trucks.

my primaries are clogged but my manifold is not, solution?