Cylinder 1 misfire and other codes

A quick Google search shows that other Toyota owners have had P0138 and P0607 together. It may be possible that the O2 sensor out of range does something funny to the ECM, and clearing the O2 problem with a tuneup generally fixes everything. A fault in cylinder 1 (possibly fuel injector since you changed plugs) could be the root cause.

Have you checked the voltage on your 12V battery? Search the forum for the procedure and thresholds. In short, it should read about 12.6 with no load, and 12.4 in ACC mode. Low 12V plays havoc with the computers.

And you may want to post in the Gen 3 forum, in case it's substantially different in this area than the Gen 2.

 

Could be very simple. If it was sitting several days and it only did it when you first fired it up it's probably just a vapor lock problem that happens after sitting long periods.
Doesn't seem to hurt anything.

If that's the case usually just turning it off and back on will fix it, otherwise put it on gear and drive it to clear the vapor lock in usually seconds.

 

there's something wrong with your meter. 12v batteries don't read 13.6 stone cold.

 

AGM batteries could, if he measured it immediately after switching the car off.

This is why you have the P0138 code. The B1S2 O2 sensor should show a consistent voltage. You need to check the efficiency of the cat to find the root cause of the sensor voltage fluctuating.

 

understood, thanks.

 

Pretty sure, your 12 V is not the problem. I'd ignore the P0607 to do with the Cruise Control, for the moment – it may be a red herring, or a totally separate problem.

P0031 = Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)

This code is saying that low voltage is detected on the heater circuit of the air/fuel ratio sensor. This is the pre-cat sensor (B1S1).

The P0138 indicates high voltage on the B1S2 sensor (the post-cat o2 sensor). You need to verify the operation of the B1S1 sensor and replace if you find it is defective. Clear the codes and see how the both sensors looks after that.

EDIT: Our posts crossed. I misread your post where you said it was the B1S1.

So is the other code P0301?

 

Ok, understood. A bit spooky that the P0031 is a code for the B1S1 sensor.

The other codes could have been fallout of the low 12 V battery which resulted in you having to have a jump. If they don't come back, I'd go with that.

Don't have any further ideas on the misfire, but would be loathe to say that it points to a ECM failure. I believe used ones are cheap from a salvage yard, but they are cheap because there is low demand as these are really reliable. But if you wanted to take a punt and replace it, that is your call.

In terms of drivability, where do you notice the misfire? Just on idle?

Has the car ever been run low on oil?

 

Ok.

Ok.

Which code are you talking about?

 

Possibly because of a one-off anomaly caused by the low 12 V on the CAN-BUS when you have the flat battery.

I was only suggesting the ECM as it may be causing the mis-fire as the mis-fire did not follow the coil when you swapped it. However, the injector and related systems can also be a suspects.

However, I am loathe to suggest a faulty ECM as there could be other reasons, for example an intermittently faulty sensor feeding bad data to the ECM.

But I'm probably at the limits of how I can help, so I am really hoping some other members will be able to chip in with advice.

 

Are you the DIY type? Have you pulled the egr pipe and seen if there is any carbon buildup? What did the old spark plugs look like when you replaced them? Cleaned the MAF sensor? Throttle body? What type of gas do you buy? Top tier or whatever is available when you need it?

Keep us posted.

 

Many of these have videos in the Gen 3 maintenance section. @NutzAboutBolts has a lot of the normal maintenance activities covered in the videos. They are helpful.

For your answers, was there a dark "halo" on the porcelain? Rust on the metal might indicate water pooling on top of the plug. I know it has been raining out here pretty good recently, is your engine bay getting wet, like the hood not seating properly? Did you get the spark plugs in square?

Who is your main source of gas? Chevron, Shell, Arco? What did you see after using sea foam? Use any other fuel injector cleaner?

With 130 k miles on the clock for a 2012, sounds like you do a lot of highway driving. Any oil consumption? If so, how much? What is your normal traveling speed?

What is your oil level at?

Sorry for all the questions, but there are a lot of great trouble shooters on this forum and you never know what answer may trigger an insight.

 

Have checked spark plug gap.....did fuel you filled last time have water .......

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