O2 Sensor and Knock Sensor Problem

[JY116]

I noticed my check engine light about a week ago after 2 events:

1. I ran over a curb after skidding in the rain. Was loud bumnps and scrapes for ~5ft. 2. I used premium 91 octane gas for the first time since I bought the car in October.

I got the codes checked and reset at a friends shop. He said it was #33 and 34 corresponding to the Oxygen and Knock sensors. A few minutes driving and the lights went on again. Do you think it was from one of those 2 events?

My guess is that the sensors got smashed on the curb... but then again, Im not sure exactly where theyre located [exhaust mani and block are all I found from the FSM...]

Thanks for any tips or info on where/what to check

[NISTECH]

what kind of car?? kinda hard to help ya not knowing.

but no nissan's will turn on the CEL for a knock sensor code. The O2 is whats turning on the light and yes it probably got shattered internally when you hit the curb. post the info on your car may have more info on your situation.

[JY116]

Oh, sorry, its a 1991 240sx coupe. The common s13, all stock...

[JY116]

136k miles, automatic... swapping soon to 5spd...

[NISTECH]

the o2 sensor is located on the exhuast manifold,driver side of engine bay. it will be the only component with wires coming off it on the manifold. the knock sensor is buried up under the intake manifold on the passenger side of the engine,mounted to the engine block. I wouldnt worry to much about the knock sensor right now. replace the o2 have the code cleared again and drive it for like a week. The light shouldnt come back on but have the codes checked again any way and see if the knock code is back if so you need to replace the knock sensor and its sub harness(no fun to do either). the 91 octane will not really have an effect on either of those components but make sure your timing is correct. you wouldnt want any preignition goin on.

[JY116]

Alright, thanks :]

another guy i spoke to said CEL throws the O2 sensor code when the spark plugs are bad... Maybe Ill give those a look, and replace whichever part is cheaper... unless hte sensor is destroyed and the obvious problem...

Thanks again!