I have a 2000 Toyota Sienna that has had a check engine light for a while. The light would come at times, and go away at others, with prolonged intervals (days, weeks, months) with or without the light.
Suddenly it started losing power, especially on hills (even a small hill). The codes I read are (I include code interpretations from internet search):
P0300: Random or multiple misfire.
P0301: Cylinder 1 misfire.
P0304: Cylinder 4 misfire.
P1130: Air fuel sensor
P1150: I have not found a problem definition for this code.
Might these codes be indicative of a particular problem, or is each problem more likely a problem with its own cause?
Since we don’t know the maintenance history or the odometer mileage of this vehicle, some of this will be speculation, but it is very possible that you only need to replace the spark plugs and the air/fuel ratio sensor.
What can you tell us–in detail–about the car’s maintenance history?
The P1130 code should be addressed first. This code indicates that this sensor is having a problem figuring out the air/fuel ratio. And this can cause the other codes.
These are the two primary O2 sensors. I’d say these sensor malfunctions may be leading to to mis-fires, and those mis-fires can cause other damage. I’d test the sensors to find the fault, fix the fault, then follow up with fresh set of spark plugs.
@BustedKnuckles while I agree with you about the importance of those AF sensors, it’s fairly well known that Toyota had some issues with those coils. But I would also replace the plugs before throwing coils at it. But in the end, I believe the OP will be needing those coils. You could always get the denso coils and plugs from rockauto.com or amazon to save some money.
Thank you all, for the thoughts. As for maintenance history,the ignition coil was replaced at around 106k - now the car has 181k miles on it. . I thought all spark plugs were replaced at the same time as the coil, but my records show that only one (cell 6) was replaced. I have the car on racks now, ready to replace both Sensor 1s. I took out the easier to remove of the two, and there is lots of greyish-white build up on it. The other one is a pain in backside, literraly as figuratively. I am going to the store to look for a simple 7/8th wrench as the oxygen sensor socket is too big for navigation in the little space of the O2 sensor.
Caddyman, you suggest I replace all of the sensors. My idea was to replace the 2 I mention above, and leave Sensor 2 in place (it seems I have only one). Do you think there is a downside to this?
I plan to replace the spark plugs but I am thinking of finishing the sensors job first and running the car for some 20 miles or so to see what codes may return. I don’t think that would be enough time to affect the new sensors even if there is a relation between spark plug problems and O2 sensors - but I am just guessing here, so any expert opinion on this would be appreciated.
@Kimland, I would replace coil #1 and coil #4, since they are setting codes. I would also consider replacing the plugs again, as you’ll need to remove at least 2 coils anyways.
I would replace only the 2 oxygen sensors mentioned in that TSB I posted. Replacing all is going to cost a lot more. As I stated earlier, I highly recommend Denso parts.
There is no “relation between spark plug problems and O2 sensors” The O2 sensors seem to be the cause of P1130 and P1150. The plugs might have a role in the misfire codes, but I’m leaning towards the coils.
Since the rear bank is a PITA to get to, I highly recommend replacing all of the coils that haven’t yet been replaced (except #6, which you already did). You wouldn’t want to do this every few months.
Here is the cylinder bank layout and O2 sensor location, in case there is any question. Toyota’s cylinder bank layout is different than some of the other manufacturers, as you can tell.
I had picked Bosch # 13355 before I saw your advise to use Denso parts. It turns out the housing end that should go into the electrical harness is mildly different from the old part (having 2 bumps on the lower side (opposite the side with the little extrusion to which the springy peg latches on). This means the part is not a perfect fit from the outside - you could force it in there, but I reason if it is not a perfect fit then it is not the right one. Fortunately my store is till open, but i doubt they will have Denso. I am returning this anyway. I can find Denso parts locally tomorrow. Cheers!
@Kimland here’s what is going on. Bosch #13355 is an oxygen sensor. Since it doesn’t fit, your car is most likely equipped with an air/fuel ratio sensor. I’m not going into any lengthy explanation, but they are NOT the same thing. The connectors are different so that you don’t plug in the wrong part. Some guys actually force them to fit and regret it later on.
This might fit, if Bosch is all that store has in stock. It IS an a/f ratio sensor
Oh my, these things are not cheap. California emission standards are costing me a heck here, and I have never been to California. The Bosch 13355 that I had picked was for the same car without California standards. With california standards I will have to pay over 2X what I was to pay otherwise. Done with the rant now.
@db4690, would you say CarQuest have got it wrong? Their part matching search returns different specifications for Left & Right, with the part you identified being indicated for Left. See below:
CQ/DENSO O2 SENSORS OE Style
Air- Fuel Ratio Sensor Upstream Left
Part Number : 234-9007 Price: $210.32
CQ/DENSO O2 SENSORS OE Style
Air- Fuel Ratio Sensor Upstream Right
Part Number : 234-9009 Price: $261.98
Oxygen Sensor Upstream
Might the following also be a fit for Sienna 2000, Upstream O2 sensors?
CQ/DENSO O2 SENSORS Wideband A/F Sensor - OE Type - Exact Fit
Air- Fuel Ratio Sensor Front
Part Number : 75-2500
@db4690, I am waiting for the parts to be delivered. Meanwhile I want to order spark plugs so i ready to go as soon as the sensors are in. I have done some search but I do not find any specification of spark plugs to the car. I can’t imagine that you could pick any spark plug you find, so I am thinking I have probably not found the right sources. Do you have insights?
I replaced the oxygen sensors today. Consequently error codes P1130 and P1150 are no more. Misfires are still present, most felt on hills: P0300, P0301, and P0304 returned with MIL ON.
I will replace plugs 1 and 4 tomorrow then take on another test drive. I suspect though this will end up being an ignation coil problem - just a gut feeling.