2000 4runner running to rich?

Question

check engine light will not turn off. Have changed both air sensors per request of a mechanic. any suggestions. EGR valve, Mass airflow sensor, any ideas?

Answer 1

Have the Toyota dealer check it, they will actually be able to diagnose the problem. Or you can keep throwing parts at it, eventually you are bound to find the right one!!

Answer 2

I don't know, but my 1999 4Runner does the same. Most times, if I get the light, I remove my gas cap (vapor lock) and then put it back on. This seems to make the engine light go off (most times). Hope this helps.

PS I had a Toyota Dealer check this for me....as I was alarmed. It was the dealer that told me to do this and he said that the sensor was too sensitive (vapor lock) and why this light comes on. Apparently, dealers are aware of this problem, but nothing is done about it, because it is just an over sensitive sensor.

Answer 3

Running too rich is a tricky one to find. Look for a collapsed vacuum line. or, try switching to a hotter burning spark plug. An egr valve and a mass air would make the vehicle's engine run funny. You would notice the problem. Everyone seems to think its always the o2sensors. They usually go out around 200k miles. Just because a scanner says o2 sensor reads too rich or too lean doesn't mean they're bad. All they read is o2, that's it. Its usually something else that causes them to read bad.

Answer 4

You need to check the code. It will tell you exactly what code set off the light. You need a real mechanic to check it. Stop throwing parts at it, you are wasting your money.

Answer 5

You may want to reset the computer by disconnecting the battery for a few minutes.

A computer reader will identify what the check engine light is for.

Answer 6

Just have a mechanic run a diagnostic on it and he will be able to tell you exactly why the light is on. Or buy one yourself and hook it up.