1998 Toyota Avalon OBD2 codes--what are these??

[another Todd]

P125--coolant temp to low for closed loop (temp guage shows normal in the middle of the guage)

P1153--Air fuel sensor response Bank 1 sensor 2 (is this the O2 Sensor?)

p1155--air fuel sensor heater circuit bank 1 sensor 2 (again, is this the O2 sensor?)

p1410--EGR valve position sensor circuit malfunction (???bad EGR valve???)

p1411--EGR valve position sensor range/performance (??? bad EGR valve???)

Thanks for any insight you can provide.

 

[tinmanSC]

Did you get all these codes within a short period of time?

 

[SLCraig]

If the coolant temp is too low, I would not be surprised if you could get all those codes because of it.

I had a CEL once because of a failing (open) thermostat.

I replaced the 'stat and the codes never came back. They were o2 related.

 

[tomcat27]

Check your coolant level first. as long as your temp gauge looks right, the first code is most likely the coolant temperature sensor altho it could be the termostat. (the sensor for the computer, not the gauge)

yes, the air/fuel sensor is your O2 sensor. I dont know which bank is bank one ( L or R ) but sensor 2 indicates the one after the catalytic converter.

If all of those magically appeared at once - it could be a wiring problem. altho on a 12 year old car it could simply need a few repairs.

 

[5sfe91]

If you do replace the T-stat go with a Toyota one I've used after market ones in the past and didn't have good luck with them.

 

[Trav]

The ECT sensor is what the EMC uses for coolant temp.
Even if the temp is in range a bad sensor will not provide the correct reading for the ECM.This sensor has nothing to do with the dash gauge.
Check and replace the ECT if values are not in range,you will need a 19mm deep socket.If bad and replaced reset the ECM and drive it,you may also have a bad o2 sensor but it maybe just throwing a code because of the ECM being in open loop.

Sensor values

4-7k ohms @32f
2-3k ohms @68f
0.9-1.3 ohms @104f
0.4-0.7 ohms @140f
0.2-0.4 ohms @176f

 

[KeithG]

The A/F sensors are not the O2 sensors. But, they are very similar to O2 sensors. I believe your A/F code refers to the front (i.e. easy to reach.) The 1133, 1135 codes are for the firewall side air/fuel sensor.

 

[another Todd]

Thanks for the replies. This car belongs to my deaf sister, in Tacoma WA and I am in So. Cal. so I am trying to help her diagnose this long distance. She already had $1600 in work done...although most not related to the codes...serp belts, timing belts, battery, LOF, front brakes, valve cover and intake gaskets. Then she failed a smog test, partly because she didn't drive long enough after the battery change, and partly because of codes present. The shop is recommending all kinds of repairs that don't make sense. I will advise her based on your replies which are about what I thought. Any ideas on the EGR codes?

 

[Trav]

The EGR codes will probably disappear when the ECM has the correct temperature signal.Don't worry about if its called an O2 sensor or AFR sensor,they both do in effect the same job and are in the same location as "normal" O2 sensors,the are AKA wide band O2 sensors.

 

[Vikas]

She also needs to find a better shop. After spending $1600, the car should not be throwing these codes. How long ago was the work done before the codes came?

Why does the car have wideband post catalytic sensor? I believe the codes are really for Bank 2 Sensor 1. (I just verified that via Google, P1153 and P1155 codes are for *primary* sensor) This is the primary sensor. Which one would be Bank 2 on a Toyota V6? I know on Honda and Nissan, Bank 2 would closer to the radiator. Because the car is throwing both signal and heater code, it is more likely that wiring has a flaw.

Anyway, only after the engine coolant temperature is investigated (either low coolant, bad thermostat or bad ECT sensor) and fixed one should spend time on the other codes.