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2008 Toyota Tacoma 4×4 2.7L 4 Cylinder Manual Trans. 69,000 Miles. I am new to this forum although I have watched many, many ETCG videos on youtube and figured this would be a great place to check. In a perfect world ETCG would be my neighbor. If only things could be so simple.
I’m just going to copy and paste the post I put up in a Tacoma forum.
SO…
Today me and my Uncle took off my plenum. It was filthy and needed to be cleaned (the reasons for that can be found here Filthy Air Intake System.
We got that all off. Stuck it in his parts washer and cleaned it out as best as we could. Blasted some air from a compressor down into it to make sure it was free of loose debris. We stuck that bastard back on and put everything else back together. I fired up the truck and it ran normally. I drove it on the freeway for about 30 minutes. No problems.
I go to the car wash and to give it a bath. I was spraying junks of mud off of parts of the skid plates and frame.
I go to start it up and the starter souded, funny and it didn’t idle very well. Let it sit for a while then tried to start it again and it really struggled getting started. There was a decent amount of additional vibration (at idle).
I get back on the freeway to go home and it runs fine on the freeway. Solid 45 minutes of driving. There has been no indication this entire time as to a loss of power or performance.
My check engine light has been perpetually on (this whole time) because of my stupid Evap Emission control system. I’ve had this checked twice and it’s this stupid system that has a tiny leak that has ZERO effect on how it runs/drives/idles. Now I figure I might as well get a scanner hooked up to make sure there aren’t any additional codes considering how strange it’s behaving. This is what I find from AutoZone.
P0012
-Camshaft position “A”- timin over advanced bank 1
1. Blocked oil passage
2. Mechanical Timing fault
3. Failed OCV
4. VVT controller assembly faultP0301
-Cylinder 1 misfire detected
1. Weak/Missing spark
2. Plugged fuel injector
3. Engine mechanical fault
4. Large vacuum leak specific to cylinderP0031
-Oxygen sensor heater control circuit low- bank1 sensor 1
1. Open or short circuit condition
2. Poor electrical connection
3. Failed Oxygen sensor
4. EFI relay faultAnd yes, I double checked to make sure that all hoses and connectors were back where they started out today before we took the plenum off. Like I said earlier, there is zero loss of power and the truck drives exactly like it did before any of this started (aside from taking much longer than normal to start).
I talked to the manager, Pedro, who really sounded like he new his stuff. I was very inclined to take the advice he gave (of all the guys I’ve talked to at this particular AutoZone this was one of the few guys who really sounded confident and very educated about automotive stuff). He believes the number one culprit is the camshaft sensor. His second guess would be oxygen sensor on the exhaust before the catalytic converter.
He said the cam sensor would cause it to struggle to start and could throw all three of those codes. The reason he puts the oxygen sensor at number 2 is that I could have sprayed it really good while washing the underside of my truck.
The thing that makes this all very, very confusing was that while we were sitting there talking about all this stuff, my truck’s idle smoothed out. Pedro put his hand on top of the valve cover and commented about how smoothly is was running now.
I just now went out to start it and it’s still taking longer than normal to start. I’ve called a few repair shops already about getting the sensor diagnosed and I was told about $140 just to diagnose the problem. If I could get some insight on how to diagnose the sensor myself I would really appreciate it. 140 just to be told, “It’s good” or “it’s bad” is not ok with me.
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[quote=”FRYBOTH” post=31780]I can’t say I’ve checked for fuel pressure. I don’t actually know how to be honest. But how does that explain how easily it starts in the morning after sitting overnight?
Ok, sorry, I must have missed that part. I thought it was hard starting all the time. Don’t remember seeing that it was easy starting in the morning ’till this post.
I’m getting closer and closer to just taking it to a shop :sick:
It’s just all so confusing and it’s keeping me up at night!
*UPDATE*
Today the misfire code is gone. I just had it hooked up and it came back with the camshaft sensor and the O2 sensor. Now, I’m leaning even closer to the camshaft sensor acting up. Could the cam sensor not reading right throw everything off and cause the o2 sensor to throw a code? Or, are both of them, for whatever reason, crapped out?
I’m not a fan of pressure washing engines for this very reason but that’s beside the point I think. I agree that the cam sensor is the most likely culprit and a heater code for an O2 almost always means you need an O2 but the fact that you pressure washed in that area might mean that water got into the connector or something. Those connectors are meant to keep out rain water not pressurized water. You might be wise to check the connectors at the very least for the O2 in question and the cam sensor, if they are wet or show signs of contamination you might clean them out and recheck for the condition.
The only way I think water got in the engine compartment was through these holes in the wheel wells where the upper control arms come through. The thing with the cam sensor is that its way up in the top of the engine block on the front (duh lol). I took the connector off of the cam sensor and everything was free of corrosion and the gasket was in good shape. If the o2 sensor got sprayed (which is very likely considering where I was washing) would that cause the cam sensor to read things incorrectly? Given the location of the cam sensor I find it hard to believe I could have sprayed it enough to screw it up. Given the circumstances the o2 sensor seems like the most likely to have gotten sprayed in a bad way. Which is why I don’t understand why I’m getting a cam sensor code.
And if anyone could point me in the direction of a video that shows how to test the connection from the 02 sensor to rule out a bad connection that would be great. I know the sensors themselves aren’t cheap.
As stated earlier, you can not use a DVOM to check the operation of an 02 sensor while the vehicle is running.
However, if you just want to check the heater circuit, you need to unplug the sensor and use a DVOM on the heater circuit and check for continuity. A wiring diagram should tell you which 2 wires to ohm.
You could also do a voltage drop test on the feed and ground side of the o2 sensor circuit also.
I would look at the o2 fuses first.
As for the cam sensor, again your at the mercy of a scope. All you can do is check your power and grounds with your DVOM.
You can visually inspect it. The O2 sensor won’t effect the cam sensor however. For that code you’ll have to follow the troubleshooting for that. Don’t rule out a mechanical issue either, it could be the engine is out of time. I would focus on things that you did before the problem started however as that is the most logical explanation.
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