what is the cause of the malfunction indicator lamp in a 1999 honda accord? we tried tightening the gas cap and it's had several trips but the light is still on. the car has only about 67k miles on it.

thank you.

 

You have to get the car's trouble code(s) read/scan. With the exception of California, most auto parts store will read the trouble codes for free.

Post the actual trouble code(s), not the description when you get them.

 

AutoZone,Advance and O'reilys have that scanner and will read your car for you.

WheelBrokerAng

 

ok, went to autozone and the codes are P1166 and P1167 and the definitions of these codes are similar. primary H02S heater system. probable cause: open or short circuit condition, poor electrical connection and failed H02S (heated oxygen sensor).

what do you think? should it be expensive to fix? what will this do to the car?

 

P1166 is Air/Fuel (Sensor 1) heater circuit malfunction.
P1167 is Air/Fuel (Sensor 1) heater system malfunction.

1. Both codes are related to the same primary sensor, located in the front of the engine. See attached picture. Your car is most likely a ULEV (Ultra Low Emission Vehicle) due to those codes. A/F sensors are a wide band type of oxygen sensor and generally a little bit more expensive than the regular narrow band sensor.

https://www.hondaaccordforum.com/for...-af-sensor-jpg

2. Check the following fuses:

• Driver's side under-dash fuse no. 6 (15A).
• Passenger's side under-dash fuse no. 6 (20A).

https://www.hondaaccordforum.com/for...-fuse-no-6-jpg

https://www.hondaaccordforum.com/for...-fuse-no-6-jpg

Most likely the air fuel ratio sensor needs replacement though. Without any diagnosis charge, it will probably be about 1/2 hour labor to replace along with the cost of the part.

If the sensor is not performing properly, it may cause some fuel economy and/or performance issues.

 

thanks red bull. you indicated to check fuse no. 5 on the passenger's side but you highlighted no. 6 instead on the diagram. is it 5 or 6? i assume that the fix might only require those two new fuses as opposed to replacing the sensor?

 

either way, it doesn't sound like a fix that has to happen immediately, correct? can it wait for a couple of weeks and can the car be driven during that time without damaging the engine or any other part?

 

They both should be no. 6; I corrected the above post. There is a lesser probability it is due to one of the fuses.

It can probably wait and be driven for a few weeks. However, if it runs rich due to that sensor, it can have a detrimental effect on the catalytic converter over a longer period of time.