How To Fix "Running Rich"...

OK now I'm more confused than I was before...

After continuing to study on the situation, I stumbled across some YouTube videos where it demonstrated how to check for bad coil packs. So I tried. Here is what I did;

1. Uncliped and loosend each wiring connector from each individual coil pack so that I would not have to deal with that task as engine was running.
2. With all connections lightly connected at terminals, I started up the engine.
3. Removed connector from cyl.#1 while engine was running and engine died. RESULT: Good coil pack @ cyl.#1
4. Reconnected terminal @ cyl.#1 and started up engine again.
5. Removed connector from cyl.#2 while engine was running and engine died. RESULT: Good coil pack @ cyl.#2
6. Reconnected terminal @ cyl.#2 and started up engine again.
7. Removed connector from cyl.#3 while engine was running and engine died. RESULT: Good coil pack @ cyl.#3
8. Reconnected terminal @ cyl.#3 and started up engine again.
9. Removed connector from cyl.#4 while engine was running and engine died. RESULT: Good coil pack @ cyl.#4
10. Reconnected terminal @ cyl.#4 and started up engine again.

CONCLUSION: All coil packs are in good working order.

So based on that, my theory of a faulty coil pack or distributor type component/part causing the CEL code P0302 gets eliminated. With that said, what other issue could target a misfire in a single specific cylinder?

I assume other faulty factors or components (ex. faulty EGR, Coolant Temp Sensor, O2 Sensor, etc.) would trigger misfire clear across the board with ALL cylinders, but what would point out an individual cylinder to be bad? In this case... cyl.#2.

Thanks again!!!

 

Switch the injectors around, see if the code follows.

 

Sometimes it is worth the $$ to take it to the dealer and get a diagnostic from their Toyota machines. You have multiple symptoms it could be an ECU issue that is not going to come up on you scangauge. It could also be as simple as a bad ground somewhere or loose connection. You are on the right track though, electrical is always the weakest link.

Good Luck


I'll keep watching to see what what happens

 

I'm an AutoZoner Always willing to help to those who want it!
yes you would have to reset the CEL if you switch wires, coils, and such. Reason being is that the code will not "clear" itself right away. It has to be run through a certain amount of cycles before the ecu says "ok all is good!" And the light goes away. Disconnecting the battery clears the codes on the ecu, allowing you to start from the beginning. Code p0300 is a random multiple cyl misfire, it could mean another cyl "might" be missing as well and isn't recorded yet on the ecu. Its difficult to tell unless you know your truck really well and can "feel" it. (yes become one with taco!) as for the MAF if uuu cleaned it with approved maf sensor cleaner, then you shouldn't have messed anything up unless something was already broken, but its hard to tell with those maf's and small wires. Uuu could replace it, but that's not a guarantee its going to fix anything. If all else fails, take it to a stealership I know its hard to say those words, but its better than racking your brain and stressing yourself out. I hope i provided at least some insight!

 

what about a crank sensor? but yes reset the ecu for about an hr and see what comes up... if that doesnt help might be the ecu.... look at your oil dip stick... if it has a cloudy milky resedue on it. its a head gasket. also check the compression in the cyclinders and do a leak down test on the radiator

 

Oh wow...!!!

The sputtering engine symptom has now been solved!!!

This time around though, I won't make my post so long, boring, and tidious to read. So quick and simple, the problem was a faulty plug that had a hairline crack in the ceramic area. Replaced the plug, and engine ran smooth as always.

Other issue with Catalytic Converters and P0420 codes is still present, but at least with that I still have a sense of direction.

Going back to the sputtering engine though, thanks a bunch guys for all your help and input into the situation. And though none of us had suggested the single spark plug as the culprit, if it wasn't for all your thoughts and suggestions, I would not have kept going back to the problem to ultimately think, rethink, and again rethink the situation until finally figuring out the solution. So again guys... thanks!!!

Oh yeah... and as for the small leaks, I finally did find out it is my water pump that needs to get changed out. Now I got to figure out how to do that since I have NEVER taken on a task of such on any of my previous cars/trucks. I hope I could find a DIY here on the forum for that.

Thanks again guys!!!

 

WP is pretty easy. Remove serpentine belt, remove fan, drain radiator, remove WP, install new WP...
It should take hand tools from 8mm-14mm and about 2hrs. Make sure you clean all old gasket off with a gasket scraper(aluminum will score easily from screwdrivers and knives). Use the same type of gasket/sealant that was on the old WP. Refill radiator with PROPYLENE glycol(pink or red, whichever was in it) not Ethylene Glycol(green).
Should be little to no sweat!

 

i told you to check all the plugs for color. that would have told you sooner...... oh and reset the codes and see if it goes away because if the plug was not fireing then the cat would look bad because of the amount of unburnt fuel going threw that cylinder.

 

I guess he didn't read our posts? good thing you got it figured out OP