Page 1 of 2

O2 Sensors

Posted: December 9th, 2004, 12:58 pm
by rinkymx3
Does anyone know what the Mazda part # is for the O2 sensors for a K8 engine?

Also, has anyone had any experience with the bosch universal O2 sensors?

Re: O2 Sensors

Posted: December 9th, 2004, 1:59 pm
by Custommx3
yes, search and ye shall find it.

Re: O2 Sensors

Posted: December 9th, 2004, 3:35 pm
by papa roached
i am using bosch, good stuff

<small>[ December 09, 2004, 02:35 PM: Message edited by: papa roached ]</small>

Re: O2 Sensors

Posted: December 9th, 2004, 3:51 pm
by fry_81
were they expensive?

Re: O2 Sensors

Posted: December 9th, 2004, 7:12 pm
by IanL
Originally posted by rinkymx3:
Does anyone know what the Mazda part # is for the O2 sensors for a K8 engine?
Front K806-18-861A
Rear K805-18-861A

The difference is probably just the cable length.

Re: O2 Sensors

Posted: December 9th, 2004, 9:59 pm
by lakersfan1
You will likely find that if you ask for sensors for a 1993 Ford Probe 2.5L, your sensors will be cheaper. The ones for the 2.5 are a direct fit, but the part numbers are different for some reason. For instance, when I went to Autozone, K8 sensors were $85 a pop, and KL sensors were only $53 a pop.

Re: O2 Sensors

Posted: December 10th, 2004, 3:39 pm
by drewleedham
i'm no a mechanic wizard, but i did a diagnostic check and i think my check engine light is on because of my 02 sensors. what might the difference in my driving experience be if my sensors were gone/going?

Re: O2 Sensors

Posted: December 10th, 2004, 4:03 pm
by johnnyb
buy some universal 4 wire o2 sensors...

ngk sells a pretty decent set all you gotta remember is how to splice the wires:


NGK Universal 4 wire O2 sensor


NGK-------->Factory
Black-------->Blue
Gray-------->White
2 White-------->2 Black

<small>[ December 10, 2004, 03:05 PM: Message edited by: johnnyb ]</small>

Re: O2 Sensors

Posted: December 10th, 2004, 6:15 pm
by drewleedham
thanks, i'll check back here when i pick some up, but i was mostly wondering if my 02 sensors were affecting my driving experience.

Re: O2 Sensors

Posted: December 10th, 2004, 9:32 pm
by johnnyb
o2 sensors will affect performance because it tells the ecu if there is too much or too little gas being injected into the engine. although it isnt a huge performance gain every little thing helps. Also if your o2 sensors are bad you'll have bad emissions coming out of your car, so environmentally its a good idea to change too

Re: O2 Sensors

Posted: December 10th, 2004, 11:39 pm
by TsiMiata
O2 sensors will not effect performance. They are only used by the ecu when you are cruising around. Under heavy loads, acceleration they are not used. If they are bad they will effect emissions and gas mileage though.

Re: O2 Sensors

Posted: December 10th, 2004, 11:58 pm
by johnnyb
they will affect performance... if they arent working properly they will send the wrong signal to the ecu telling it to send more gas to the engine, now with too much gas to air ratio the engine doesnt run correctly and in turn lowers your performance.

Re: O2 Sensors

Posted: December 11th, 2004, 1:10 am
by babyblueMX3
what tsimiata was trying to say is that performance is when we are WOT and at WOT they don't use the o2 signals. who needs performance when you're cruising :shrug: They will afect gas mileage though

Re: O2 Sensors

Posted: December 11th, 2004, 1:20 am
by papa roached
at WOT the ECU goes into closed loop mode, it ignores all sensor inputs

Re: O2 Sensors

Posted: December 11th, 2004, 3:28 am
by IanL
Originally posted by papa roached:
at WOT the ECU goes into closed loop mode, it ignores all sensor inputs
Small correction; at WOT the ECU goes into open loop mode, which uses mapped values for fuel (but still uses the coolant temperature and VAF signals), and ignores the O2 sensors.

Under cruising conditions, the ECU runs in closed loop mode, which uses the O2 sensors as well. So it's correct to say that performance at WOT will not be affected by the O2 sensors, but economy and emissions whilst cruising will be.