Volvo Owners Forum banner
1 - 5 of 5 Posts

· Registered
8 Posts
Discussion Starter · #1 ·
I've been reading up on O2 sensors and their effects on fuel efficiency. I feel like my 240 isn't getting it's maximum Km per L of gas and was thinking that I could have a malfunctioning sensor.

My questions:

1) Is there a way to know if you're O2 sensor is malfunctioning?

2) If installing a new O2 sensor in my 1984 240 should I install a single wire or a three wire sensor?

I know that the three wire sensor makes the sensor effective more quickly - but it is also three times the price. Since my car is old I was hoping to just install a single wire O2 sensor.... will that work?

Thanks for everyone's input!


· Volvo Guru !
5,911 Posts
You can install the same sensor that is on there which should be the single wire.You can test it by installing a volt meter on the Green wire I think it is .The wire with the spade connector rubber on one side and plastic on the other.With the car running at normal temp the Volt meter should sweep from 0-12 Volts.One probe on the green wire and the other to ground.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.