check engine light is on

[david200095367]

i have a 91 240sx and the check engine light went on. the code it gives me is 33. what do i have to do to repair it? thanks.

david

[1991S13]

Code 33 is for the front o2 sensor.

If Im not mistaken, 91's only have one o2 sensor and it's around the middle of the header. Check that out, replacing it should fix it.

[mss5413]

Looks like DTC 33 is an O2 sensor. Probably about $30 for a bosch from autozone, but I personally suggest buying from the dealership. More money, I KNOW, but I believe if you have a japanese car, then buy a japanese replacement part.

There are a couple of ways to approach this, you can disconnect the sensor with the engine running and use a meter to check the output voltage, I think it should be around 1 volt, or you can test drive the car with the sensor disconnected and see if the car runs better than before.

The O2 sensor is located on the exhaust pipe around the headers. There should only be one, and it has only 1 wire with a wire clip on the exhaust manifold heat shield.

Good Luck and send another post if you have any questions.

[mss5413]

Sorry, I forgot to tell you. If you do replace the sensor it requires an O2 sensor socket which is available at autozone through the LOAN-A-TOOL program. $15 deposit.

[david200095367]

thanks for all the help.