I found when i accelerate my 06 Honda Accord (automatic transmission) from 0 speed to 50 mph, i felt the car jerks twice, one at 20 mph, one at 40 mph. after that, the car was running smoothely. What is the problem? does that mean the transmission is going to wore out?

Thanks!

 

Four or six cyl?

Have it scanned for codes - some codes can be stored without setting the MIL/CEL.

 

4 cylinder
I scanned the code, there are two codes: P2185-Engine coolant temperature sensor
and the other one is Oxygen sensor.

Is the temperature sensor on the engine block or the radiator?

 

I'll assume the issue happens all the time

P2185 is for ECT 2, which is on the rad....HOWEVER, I'd be more concerned with the "O2 Code" based upon your description of the issue.

So, again I'm more interested in solving the "O2 sensor code" - code PLEASE - than the 2185.

In general - don't know the actual code - the O2 sends fuel ratio/trims to the PCM. So if there is something wrong in that circuit you are going to have issues like you describe.

 

The O2 sensor code is P1157, is it easy to replace the O2 sensor? and i heard there are two O2 sensor in this car. One below the engine, one is on the back of the car. Which one i should replace?

 

While I hate to replace things without testing....there are all kinds of things that could throw off the O2 sensor.....exhaust leak, short in a wire, ect.

P1157 is something with Sensor 1, which is the one just below where the exhaust manifold joins the front exhaust pipe - before the cat converter.

If you have a choice and are going to get a replacement, I highly suggest using a Denso brand replacement.

 

I see, so it is the upstream O2 sensor, right? I have located this sensor and try to unplug it for a test, however, I have a hard time to unplug it from the connector, it is very tight and my hand has very limited space to do that, any suggestions to unplug it from the connector? not the other end joining the exhaust pipe.

 

I unplugged the sensor from the connector and i use a multimeter to measure the resistance between two black wire, the reading is 2.8 ohms, so does it mean the O2 sensor is OK? how can i do any further test?

 

Sounds like you tested the heater circuit....(p0134~P0135 codes).

High level - use proper service manual procedures - with the "1157 code" you are checking the connections of the other two wires back to the PCM. Again, be sure there are no exhaust leaks as that will also throw off the O2 readings.

 

I replaced the upstream O2 sensor today. Now the code 2185 and 1157 have gone, but there is a new code: P0135, the O2 sensor heater circuit high, what is the problem? it is a new O2 sensor, i doubt it has any problems.