Reset computer by driving @ ? mph for so many miles then again @ ?mph for so many miles after disconecting battery to clear codes

SOURCE: Code P0401 1998 Toyota Camry

I'm assuming that it is a four cyl.The p0401 code is for insufficient egr flow.Most of the time it is the egr vsv valve (vsv means vacuum switching valve)which is what controls the vacuum to the egr valve to open it.It is kind of hard to get to as it is on the block under the head on the back side.If you follow the hose from the egr valve it goes to the vsv.I have also seen mice eat holes in the vacuum line which would also give you problems.I hope this help and let me know if you have anymore questions

SOURCE: 2001 toyota corolla check engine

Mass Air Flow sensor! Just remove your air filter cover. Go to Auto Zone and purchase some solvent. Spray past the air filter and it should correct the problem. If not, replace the Mass air-flow sensor. This is commonly mistaken for an oxygen sensor. Mine did this and I followed these steps and it fixed the light. BTW, the light stayed on for 5 years before I fixed it. Never hurt anything. It's normally something to do with emissions. Dummy lights. :)

SOURCE: check engine light

It could be a few different things but most likely it is the Oxygen Sensor (O2 Sensor) The only way to really know is to go to your local autoparts store and use there loaner On board diagnostics tool...there is a plug in somewhere under the drivers side dash...turn the OBD reader on after is is pluged in and then it will instruct you to turn the vehicle on...after a few min, it will produce a "trouble code" Look in a Haynes repair manual and match the code to your code and it will reveal the problem...replace the faulty part and the check engine light should go away.

Dar

• 2007 Answers
• Posted on May 13, 2009

SOURCE: 1998 toyota corolla shakes before 2 rpm, check engine lights up

Not sure what is causing it, but it sounds like you're running on 3 cyllinders. Check plugs, wires, timing . timing belt may have jumped, bad injector, low fuel pressure.

SOURCE: code P0125 keeps coming up, obd system does not

Hi,

The p0125 code is an oxygen sensor code, the description will say something like" insufficient coolant temp for closed loop operation" the problem is not the coolant temp sensor, the problem is that the signal from the O2 sensor is not within the parameters that the computer needs to go into a closed loop condition, more than likely replacing the O2 sensor will take care of the problem but only if there is not another problem with the engine such as a misfire, vacuum leak or a mechanical problem, from what you've said this doesn't seem to be the case, so before spending a lot of time diagnosing replace the sensor.

Thanks.