If you have a xrunner you won't have dual VVT. Does it throw a code for timing being over advanced or anything?

I had this same issue one time where it said one side was lean and one side was rich. When I had my trans out the harness for the o2 sensors spun around and when I hooked them back up they were plugged in to the opposite sides of the harness. This will cause 1 side to read lean, and the other to read rich.

Before you start tearing the motor open and replacing a bunch of parts, verify that your o2 sensors by the transmission are plugged into the correct plugs on the harness. Or just unplug them both, and plug them back into the opposite plugs and see if the code goes away.

SgtBadA said:

If you have a xrunner you won't have dual VVT. Does it throw a code for timing being over advanced or anything?

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Yes it's not duel ...... I realized single is actually duel and duel is actually
Quad vvt . No I don't have any correlation codes as far as timing . But I replaced drivers bank injectors . I'm reading 180 on all three cylinders in a compression test . Plenty of fire coming from coils/ plugs ..... and it's isn't all the time . When it does start misfiring. It. Will. Always throw 2-4-6. If I clear the code it will run fine ..... I believe the intake timing gear (vvt gear ) is defective. And. Throwing my timing off one that bank . I've already ordered a new one and will keep you posted if it fixes my problem . Should be Wednesday roughly

justin13703 said:

I had this same issue one time where it said one side was lean and one side was rich. When I had my trans out the harness for the o2 sensors spun around and when I hooked them back up they were plugged in to the opposite sides of the harness. This will cause 1 side to read lean, and the other to read rich.

Before you start tearing the motor open and replacing a bunch of parts, verify that your o2 sensors by the transmission are plugged into the correct plugs on the harness. Or just unplug them both, and plug them back into the opposite plugs and see if the code goes away.

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I will verify. The o2 sensors weren't swapped around during the exhaust install .

O2 sensors are. In correct location . And reading well . Thanks for suggestion . Going to have to go internal !

Sounds to me like you have vacuum leaks in your hoses. I would start there. Not the VVT gear.

Vacuum leak was the first thing I checked for . Always start with the basics

I can hear a sort of. Knock . Not bad . Seems almost like a chain slap . Once I take down front cover I'll be sure to keep
Posted

Have you done a compression test yet?

Then do verify the O2 sensors are plugged in correctly. Reset the codes, then unplug hte right rear O2 sensor (passenger) and drive it until a code sets. The code should be for B1S2 heater failure. If it comes back as B2, it is plugged into the wrong side. Then do the same for the front right sensor. Do this BEFORE you take anything else apart.

Gadget said:

Have you done a compression test yet?

Then do verify the O2 sensors are plugged in correctly. Reset the codes, then unplug hte right rear O2 sensor (passenger) and drive it until a code sets. The code should be for B1S2 heater failure. If it comes back as B2, it is plugged into the wrong side. Then do the same for the front right sensor. Do this BEFORE you take anything else apart.

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This is the best way to verify those o2 sensors are in correctly. It really sounds to me like this is your issue since one side reads lean and the other side reads rich.

Guys guys. He wants to do engine archaeology. Let him be.

Gadget said:

Have you done a compression test yet?

Then do verify the O2 sensors are plugged in correctly. Reset the codes, then unplug hte right rear O2 sensor (passenger) and drive it until a code sets. The code should be for B1S2 heater failure. If it comes back as B2, it is plugged into the wrong side. Then do the same for the front right sensor. Do this BEFORE you take anything else apart.

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Yes compression test read 180. On all three cylinders . And. My 02 sensors are plugged in correctly and functioning . I swapped the plugs yesterday to verify when Justin had mentioned that . Thanks for input ! I'm def exhausting all options before the Tare down Wednesday

Torspd said:

Guys guys. He wants to do engine archaeology. Let him be.

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Not like that at all . If I didn't want input I wouldn't have asked . I'm just letting you know where I'm at and what I've tried . Thank you guys for all suggestions . . I literally spent an hour under there yesterday. Swapping o2 sensors around . And the plugs going to the 02 sensors . Each time watching the live data on the scanner . . It's the intermittent knock/slap I get around 2500/3000 rpm that has me thinking chain. . That's all

Have you checked for vacuum leaks yet?

How regularly do you change your oil?

Tensioner could be failing. Not normal, but is possible.

Do you have the specs to determine the allowable tolerance for chain stretch?

Yes I checked for the vacuum leaks . Multiple times .
I just bought the x runner at 107k .
I don't know how regularly the oil changes where done . I'm now at 108,500.
I pulled the valve cover as well . To my
Surprise the head was very clean and the chain Seemed To be fine . It looks like it was regularly maintained and had 31 service records on carfax when I purchased . I have come across several toyotas at work with failed injectors so that was my initial Assumption . checked the spray pattern for injectors , No leaks seemed fine . Fuel pressure is great .
. Still swapped all three injectors on drivers bank. New plugs . I swapped the coil packs. To see if my misfire code changed to 1-3-5. No go . Stayed on same bank . So I swapped coil packs back . Yesterday is when I tried swapping the 02 sensor plugs. When I swapped the 02 plugs I got the code for the proper banks . So those where good . The compression test. And hydrocarbon test Come back good .
So I don't feel like I have a blown head or cracked piston . I even have stock exhaust manifolds and cats still on . Vvt is something I'm unfamiliar with . And I had read a fair amount about them failing . Me being stumped is why I was leaning that way . I was just thinking maybe someone had Been through this before . I read the main chain tensioner is a ratcheting style and reusable ?
I would like to think one hasn't failed . I'm just skeptical not knowing the trucks history . And I'd rather rebuild than destroy if you feel me .
I've had the displeasure of rebuilding several triton engines . So maybe I just have a bad taste in my mouth about Vvt . I need come into the new age I suppose .

I had a tundra misfiring on a cylinder and ended up being a broken valve spring. If ur valve cover is off check all the valve springs and valve clearance and rotate the crank to watch everything and check all. Usually when vvti has a problem it throws a code.

o0opackersfano0o said:

I had a tundra misfiring on a cylinder and ended up being a broken valve spring. If ur valve cover is off check all the valve springs and valve clearance and rotate the crank to watch everything and check all. Usually when vvti has a problem it throws a code.

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I will definitely do a thorough valve spring check before I tear down the front . I didn't see any damage at first glance but I'd be lieing if I said I really checked them out . I'll do that tomorrow morning !

It is a very big job removing the front of the engine to replace that part on a guess.

I would suggest that you run the diagnostic process for the code you are getting before you do all that work.

That's what I've done gadget . Like I said it exhausting all options before a tear down . once I find it . I will post pictures of the culprit