This is probably the best place to post this since there's not a ton of information out there on replacing these. Hopefully the tundra/sequoia people know how to use google. This is just for people getting a P0012/P0022 after changing their o-rings.
If you're replacing the cam seals there's no reason to not replace the o-ring, especially with how old these engines are getting. Both mine were rock hard at 226k.
FSM calls for replacing the entire VVTI assembly (13050-50021). I bought a pack of 5 o-rings (1288N363) from McMaster-carr for $22 total. You'll also need a T30 tamperproof torx plus bit to remove the VVTI cap.
For those who haven't replaced them:
Both youtube videos only mark where the VVTI cap aligns to the VVTI assembly. You also need to mark the positions of each bolt on the cap. The caps holes that the bolts pass through allow the cap to just slightly clock itself a couple degrees back and forth. If it's reassembled just slightly off you run the chance of causing a CEL.
Once apart it's pretty simple/easy to replace the o-ring with the entire VVTI assembly removed. The cap and innards came apart as one with a couple love taps. Reassemble as it came apart, I torqued the 4 torx bolts to 72 inlbs.
For those who now have a P0012 or P0022 (or both) after replacing them:
I got both codes after my first startup. After originally clearing them thankfully my P0022 went away but my P0012 remained.
There's basically 3 things associated with this code: The solenoid, filter, and VVTI assembly.
The solenoid is easily tested. You can pull it and directly give it power to see if it's actuating correctly. In my case with the P0012 powering it directly with the engine running did not change anything. I could hear it actuating but there was no difference in engine noise. Which sent me to check the oil pressure going to the VVTI assembly: Depending on how much FIPG was used there's a chance that the filter is clogged and not enough oil is getting to the VVTI assembly. I removed the belt again (can't just remove the cam gear cap, at least on bank 1). My filter was not clogged and this was an awesome way to waste 4 hours.
This is where I remember that there's a couple degrees of play with the VVTI cap to the assembly. Luckily this can be adjusted on the car with the timing belt and everything still on.
I loosened the 4 torx bolts just enough that I could rotate the cap back/forth by using a 19mm wrench on the washer bolt (not in this picture).
First I clocked mine all the way counterclockwise. Tightened the torx back up to 72inlbs and tested it. At idle now the VVTI assembly had a "slap" noise that would go away when it was given oil pressure from the solenoid. Loosened the bolts again and clocked the cap all the way clockwise this time. No slap noise at idle, and now when directly powering the solenoid I could hear the VVTI actuating. Took it on a test drive and confirmed I have my VVTI power back.
So this fixed my P0012. I think these assemblies are sensitive enough that they need to come back together exactly as the came apart.
If you're replacing the cam seals there's no reason to not replace the o-ring, especially with how old these engines are getting. Both mine were rock hard at 226k.
FSM calls for replacing the entire VVTI assembly (13050-50021). I bought a pack of 5 o-rings (1288N363) from McMaster-carr for $22 total. You'll also need a T30 tamperproof torx plus bit to remove the VVTI cap.
For those who haven't replaced them:
Both youtube videos only mark where the VVTI cap aligns to the VVTI assembly. You also need to mark the positions of each bolt on the cap. The caps holes that the bolts pass through allow the cap to just slightly clock itself a couple degrees back and forth. If it's reassembled just slightly off you run the chance of causing a CEL.
Once apart it's pretty simple/easy to replace the o-ring with the entire VVTI assembly removed. The cap and innards came apart as one with a couple love taps. Reassemble as it came apart, I torqued the 4 torx bolts to 72 inlbs.
For those who now have a P0012 or P0022 (or both) after replacing them:
I got both codes after my first startup. After originally clearing them thankfully my P0022 went away but my P0012 remained.
There's basically 3 things associated with this code: The solenoid, filter, and VVTI assembly.
The solenoid is easily tested. You can pull it and directly give it power to see if it's actuating correctly. In my case with the P0012 powering it directly with the engine running did not change anything. I could hear it actuating but there was no difference in engine noise. Which sent me to check the oil pressure going to the VVTI assembly: Depending on how much FIPG was used there's a chance that the filter is clogged and not enough oil is getting to the VVTI assembly. I removed the belt again (can't just remove the cam gear cap, at least on bank 1). My filter was not clogged and this was an awesome way to waste 4 hours.
This is where I remember that there's a couple degrees of play with the VVTI cap to the assembly. Luckily this can be adjusted on the car with the timing belt and everything still on.
I loosened the 4 torx bolts just enough that I could rotate the cap back/forth by using a 19mm wrench on the washer bolt (not in this picture).
First I clocked mine all the way counterclockwise. Tightened the torx back up to 72inlbs and tested it. At idle now the VVTI assembly had a "slap" noise that would go away when it was given oil pressure from the solenoid. Loosened the bolts again and clocked the cap all the way clockwise this time. No slap noise at idle, and now when directly powering the solenoid I could hear the VVTI actuating. Took it on a test drive and confirmed I have my VVTI power back.
So this fixed my P0012. I think these assemblies are sensitive enough that they need to come back together exactly as the came apart.