Engine Questions. Pulling codes...

[Identify]

So I am having a problem, I just got 5 codes..

Checked them and it is this: in order

PO300 -meaning random misfire / multiple.
PO302 - cylinder 2 misfire
(x2) PO303 - cylinder 3 misfire
And last PO420 - Catalyst system Efficiency below threshold Bank 1



Does anyone one have any ideas... The only thing I can think of is that I had my exhaust done about a month ago cat back 2.5in Flow master 40 series. Maybe the guy who welded it sucks? I really don't know..

If anyone has some ideas please help me out. Thanks:cry2:

 

[jreask]

I can tell you that the 420 usually means the O2 sensor after the cat is bad. I chased that one for a few days myself. I don't know about the others.
Try the google custom search at the top of each page.

 

[TheDurk]

How old are your plugs? What brand? I'd change them for Denso or NGK double electrodes (OEM), and carefully look at each one, especially #2 and #3. Also look at your wires. If they say Sumitomo and have the year on them, they are original and need to be changed.

And like the man said, search on the codes. Address the misfire first, and you might cure the P0420. Unburnt fuel from the misfire can mess the whole catalytic control system up.

 

[Identify]

..Miiiiigggghhhhttt have found the issue.. not sure going to give it a day or to, then ill know.

from cylinder 5 where the coil pack is sitting on ( coil pack closest to passenger seat. the plug what a little loose and may be the reason, so snapped it back in and we will see tomorrow. I guess we will see haha, Plugs and wires are all brand new with NGK,

if thats not it I suppose ill start looking at O2 censer..?

 

[Identify]

Well I thought that was the case an I was wrong... Still doing it.

I also read this forum post, because its like the same symptoms.

Please Help! Cylinder #2 Misfire 3.4l - YotaTech Forums

But I dont know what I should check next any ideas??

Ill take a video of it tomorrow and post it up and see what you all think. Thanks.

 

[4R99JB]

I've mentioned this before, but its worth repeating; P0420 catylist efficiency (catylist damage) can occur when too much unburnt fuel enters the catalytic converter. In other words it is doing its job but becoming overwhelmed.

 

[Identify]

Okay that does make a lot of sense.

But here is my thought process on it and maybe someone can diagnose it

So I have done new NGK plugs Single pronged, without trying to gap them because I have heard they don't need to be because they come pre gaped.

I also have new spark plug wires (NGK)

Also have a brand new coil pack in cylinder 3, Along with a brand new injector in 3 as well, because of a previous problem with cylinder 3. (Misfiring)

So after fixing that last problem, the truck ran great no problems whats so ever for about a month

So I decide to get my exhaust done, I want to say about a month ago. Runs great sounds good yada yada

Then this last Monday, ?Bam?.. 5 codes. included a PO420.

but its been a week, still not fixed, (after thinking it could be a short in the wires, got brand new NGK wires. still nothing. Switched around coil-pack..nothing..cleans MAF..nothing..

and have gotten about 7 check engine lights in this week.. so I check them and now all they ever say is - random/multiple misfires OR it tells me witch ones are misfiring.

What I have noticed is this. Only cylinder 2 and 3 are are popping up (when I read the check engine light ) And "so far" Every time I start up the truck when its cold,(and or when it sits and cools down) it runs just fine even after it warms up,and im still driving it, BUT if I stop somewhere and turn it off, then come back and start it up when its still warm, it runs bad.

But just tonight I drove it while its running like crap, and about 15min go by of driving and it starts running right all the sudden.

I am sooo lost..Any last ideas or suggestions before I go blow 300 at a dealer.....

 

[the great him]

try swapping injectors, you might have a misfire from a bad injector, either is not dumping fuel(but from the p420 code i dont think thats the issue) or its dumping too much fuel and drowning out the spark(in essence flooding like with a carbrator). so try swapping the injectors from one side to the other and see if the code fallows

 

[the great him]

i just read your thread from a few weeks back about your "other misfire issue"- http://www.toyota-4runner.org/3rd-gen-t4rs/120591-i-can-not-figure-problem-out.html and i think these are related somehow. i would clean out the IACV, and the MAF again, replace the air filter(or clean it if its a K&N or the likes of) and change the fuel filter. that way you are making sure you are getting good air constantly, and a good constant fuel source.

 

[Identify]

ill clean the IACV and see what happens, question though on moving the injectors, So the brand new one is in cylinder 3 along with a brand new coil pack, yet I am getting miss fires for both 2 and 3, and just today a cylinder 3 again..

 

[the great him]

try moving both injectors directly across to the other side and see what happens. it would be odd that two injectors, especially with one being new would crap out at the same time, but i have seen it before, carefully inspect the O-rings on them too. and ive always been of the mind set that when replacing items i replace all of them- when one wheel bearing goes bad i replace both side(on that axle), or if a bulb burns out i replace both bulbs, when i replace a spark plug i replace all of them.... call me anal but that way you get even consistent performance out of things and you wont have one on cylinder running better than the others.

 

[Identify]

True that, yeah so I am at a lost Still have figured nothing out..

 

[4R99JB]

I was rereading this thread and also the one on YotaTech...

I was begining to think that perhaps coil pack 2 & 3 were swapped. Until you said it would intermittently worked fine.

You also mentioned that it ran better cold. The ecu also uses various sensors to determine if the truck is "warm".

Plus, I re-read your previous post, definitely the same issue.

I'm convinced it's timing. OR I have absolutely no clue. :wtf:

Please keep us informed,

 

[Identify]

I will definitely check my timing than,

So last night while working on my rig I pulled off the cover to my belts so I could change my cam censor ($89) While doing that..

What I found scared me lol..

What I believe to be my knock sensor has a open wire. As if the coding was burnt off it was all opened up starting to show wires through.. Not to mention while taking a closer look at it, something seems off, Im going to take a pic and post it here soon.

Not sure if that could be causing it, but I know its not helping it,

 

[Identify]

SOO. I gave up and took the truck in to have looked at,

Doc says its my Ignition Control Module..

and hes about 50/50 sure...

Anyone know where i can grab one?? or if anyone has one that's not $200 let me know.

 

[Granite]

You sure it's not a lean condition misfire due to unmetered air or a vacuum leak?

 

[Identify]

Going to check for vacuum leak this weekend, I think it could be the problem