Vehicle: Toyota Tacoma 2006 V6, 155K mi

Problem: I had OBDII Code P0348: Camshaft Position Sensor A and fixed it by replacing the broken camshaft position sensor. However, the check engine light didn't stay off very long. Only after about 100 mi, I got a P0101: Mass or Air flow Circuit and soon after P0022: Camshaft Position A Timing Over-Retarded Bank 2. Those are the only two codes I am currently getting. The truck does lose (most likely burn rather than leak) oil because I have to add a quart every cca 400 mi. Could the oll loss be affecting the OCV?

Q1: Some basic research indicated this might be related to the oil control valve or the VVT valve. Could the oll loss be affecting the OCV?

Q2: Another suspicion is that, when I replaced the broken camshaft position valve, I too the functional one from the driver's right and put it in the socket where the broken one was and then put the brand new sensor in the driver's right side, IOW I rotated them. I doubt this matters but can it be causing the new code?

Q3: I think the P0101 (Mass or Air flow Circuit) might be because, as I had to lift the air intake, I may have introduced a leak with one of the clamps or maybe the gasket around the air filer is not sealing too well. That is an easy fix but could it be causing or related to the P0022 (Camshaft Position A Timing Over-Retarded Bank 2)?

Q4: Are there tests I could do to narrow down the range of possibile causes or should I just go for the new OCV or even VVT? They are original, haven't been changed. Of course, the greatest concern is that the camshaft might indeed be mistimed although the truck drives just fine.

  • I'm just wondering, since you included all of the particulars in this question for the P0101 question, why didn't you just combine them, or better yet, create separate questions for all of these? Commented Jun 10, 2019 at 20:23
  • Because the other one is more specific and I didn't want to confuse with too many details
    – amphibient
    Commented Jun 10, 2019 at 20:31
  • 1
    " Camshaft Position A Timing Over-Retarded Bank 2" This issue can also cause your other code P0101
    – Moab
    Commented Jun 10, 2019 at 21:40

1 Answer 1


Q1: Unlikely, based on your info I would say it is not this, refer to below for full explanation.

Q2: This would not cause an issue unless the two sensors had to be put on a specific side, i.e. they might only work one way. This is unlikely though, so this is likely not the issue.

Q3: The air filter won't effect the code you are getting, the Air Filter is before the MAF/AFM sensor. Most likely the Camshaft Position Sensors are confusing the engine into thinking it is at a different position than it is, this is causing the engine to be confused by seeing sensor values that it would not expect.

Q4: These are most likely not the issue, and probably have nothing wrong with them. Not to be rude, but it sounds like you aren't too sure about this stuff so I wouldn't touch the OCV or VVT stuff, leave that to a mechanic, these things can cause big damage if done incorrectly. The Camshaft Position Sensor is fairly straight forward when done correctly, so if you do some research into doing it for your engine you should be able to, however it would be faster and easier to get a mechanic to do it.

My thoughts on what the issue is:

Sounds like when you installed your new Camshaft Position Sensors, you did not ensure they went in at the right angle. This is very important and almost certainly the cause of all the issues.

These work by looking for a mark on the camshaft and telling the engine computer what piston is next in the cycle. If you rotate the sensor incorrectly it is going to see that mark too early or too late. You need to get a Timing light and look into the procedure for setting the timing on your engine.

Otherwise, you need to take it to a mechanic and have them do it for you. Doing this wrong can result in engine damage so if you are not confident you should take it to a mechanic immediately.

A good tip in the future marks the old one with a sharpie before removing by drawing a line from the sensor to the engine so you can line it up when putting back in. You can compare the old sensor to the new one, put the mark in roughly the same spot and that should get you close.

  • You're correct, when I replaced the camshaft position sensor, I didn't check that the timing chain is in any specific position. Like top dead center or similar
    – amphibient
    Commented Jun 11, 2019 at 3:11
  • Yup that may be the cause, essentially, the Camshaft Position Sensor itself can be installed on multiple angles (when bolts are loose you can rotate the sensor). This essentially changes the phase of the camshaft that it detects. This means that the ECU will think the camshaft is in a different rotation than it is, and hence will not have correct ignition timing (this is why the code is Camshaft Position A Timing Over-Retarded). You can fix this by finding out how to configure the ECU to a fixed ignition timing, then use a timing light to adjust it.
    – H. Daun
    Commented Jun 11, 2019 at 3:50
  • Actually, not on my truck. There is only one way the sensor goes in and it is determined by the position of the bolt hole. I was thinking that the chain itself needs to be in a specific position when the sensor goes in.
    – amphibient
    Commented Jun 11, 2019 at 14:21
  • I did some further research and it seems like the timing chain position is irrelevant to this sensor.
    – amphibient
    Commented Jun 11, 2019 at 15:28
  • 1
    Sorry I should have looked into your specific Camshaft Position Sensor. This is quite odd then, in that case, removing the cam position sensor and replacing shouldn't cause any issues. It's possible however, that the cam chain his skipped a tooth if its tensioners are getting old. This would cause the same issue as instead of the cam sensor being out of phase, the whole cam itself is out of phase. Probably worth checking the cam timing is correct.
    – H. Daun
    Commented Jun 11, 2019 at 22:47

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