I have a 1994 4 runner with check engine light on and i just removed the o2 sen. to get to the exhaust shop so i could have the cat replaced now its all back together and runs great yet check engine light is still on how do i reset it??
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
I'm sorry you replaced the parts without testing first. Codes only give mechanics a suggested area to test, not which components to replace.
Since you replaced the O2 sensor for the first two codes, a mechanic will need to check to see if it is working by reading the data flow from the sensor with a scanner while the engine is warming up. The catalytic converter will also need to be tested to troubleshoot code 431.
Code 455 is for a leak in the evap system which is what vents the gas tank to the vapor canister. The system will need to be pressure checked for leaks and then repaired.
Keep in mind, once the repairs are made and the codes erased, the car will need to be driven at least 100 miles in various conditions before you re-test.
DTC P0131 HO2S Circuit Low Voltage Sensor 1
The PCM supplies a bias voltage of about 450 mV between the HO2S signal and low circuits. When measured with a 10 megaohm DMM, this may display as low as 350 mV. The oxygen sensor varies the voltage within a range of about 1000 mV when the exhaust is rich, down through about 100 mV when exhaust is lean. The PCM constantly monitors the HO2S signal during closed loop operation and compensates for a rich or lean condition by decreasing or increasing injector pulse width as necessary. If the HO2S 1 voltage remains excessively low for an extended period of time, DTC P0131 will be set.
Do you have a advanced scan tool to check O2 sensor data ?
This video is on a honda but your's works the same Honda Civic P0131 02 Sensor Diagnosis
exhaust doesnt sound like a code, there should be more to code than cat or exhaust, the cat code is probably like cta efficencey below thrushold. this means the converter is not working, the cause maybe bad cat or bad oxygen sensors, testing may be needed to see if o2 sensors are working good. the exhaust code i dont know, never heard of exhaust code, they may be caused by the same problem, start with the cat code, have o2 sensors (oyxgen sensor) checked or if over 100,000 miles replace them. if converter is bad it a very good thing to also replace the o2 sensors with the new cat.
It is not true that you have to replace the O2 sensors when you replace the catalytic converter. It is suggested, but not required. Most exhaust shops can test the catalytic converter for flow. before you spend the money to replace a part that does not need it.
hello there: if you replaced it by you're self you may have to drive it for awhile to get the light out it will have to go threw a drive cycle to reset some times it takes a while or you could take to a shop or parts house and find out if they could reset the light for you and if it comes back on there maybe a different problem that will be with in the same system..hope this helps you out please leave a review thanks sincerely D.Jones
The check engine light is probably indicating a catalytic converter malfunction the Oxygen sensor that is located after the cat tells the computer if the cat is functioning properly it is possible the wire has been broken or damaged. To see if the cat is there jack up the car and look under the passenger and driver area of the car follow the exhaust pipe from the front back the first thing the pipe comes to should be the cat it looks like a muffler with a wire going to a sensor after toward the back side of it, I doubt they never installed one but I guess it is possible.
start engine and bring to normal operating temp. unplug the base timing connector located in the distributor wiring harness tan wire with a black stripe
use a timing light and set timing to 0 degrees at idle the timing marks are on the crankshaft pulley and a tab on the timing cover with numerical indications
That would correct the problem, the O2 sensor is on the exhaust manifold or on the exhaust manifold down pipe. If you go to Auto Zone, they will have the O2 sensor you need and also the loaner tool you may need to remove the O2 sensor. Auto Zone also can give you the step by step instructions to replacing the O2 sensor in about 30 min. Once you located the O2 sensor, disconnect the wire harness and use the O2 sensor socket to remove the sensor from the exhaust. It's like removing a spark plug, to install the new O2 sensor is just to follow the same procedure in revers to the removal. Good luck.