2ND GEN VS 3RD GEN A/F SENSOR, Im lost in my own little world Options

[4-eyed-freek]

Hey guys, im just curious. Has anyone used a 2nd gen af sensor in their 3rd gen 3s. Are they compatible? they are different prt numbers but in cases that means nothing in the world of toyota.

[Bitter]

If they're both flap then they're likely calibrated differently, but may be the same or similar physically. I think the flaps on some can be re-tuned by changing the spring tension, I read about that for the R series a long time ago in pick up trucks and old Celica.

[Smaay]

If they're both flap then they're likely calibrated differently, but may be the same or similar physically. I think the flaps on some can be re-tuned by changing the spring tension, I read about that for the R series a long time ago in pick up trucks and old Celica.

huh?


Im pretty sure the plugs are different but thats not the problem.. the main problem would be the response of the sensor. What is the ECU looking for.

Pressure2 actually answered this question for me on MR2oc.com. he said that the 93 All-Trac or 93-95 MR2 sensor is the same as the 3rd gen.

[4-eyed-freek]

So the actual sensor is the same, only the plug end is different?

[Smaay]

i believe the plug is the same. in the case of the 93 all-Trac.

[Bitter]

If they're both flap then they're likely calibrated differently, but may be the same or similar physically. I think the flaps on some can be re-tuned by changing the spring tension, I read about that for the R series a long time ago in pick up trucks and old Celica.

huh?


Im pretty sure the plugs are different but thats not the problem.. the main problem would be the response of the sensor. What is the ECU looking for.

Pressure2 actually answered this question for me on MR2oc.com. he said that the 93 All-Trac or 93-95 MR2 sensor is the same as the 3rd gen.

The old Toyota flap AFM's, some had a screw inside to change the spring tension on the flap and alter how much air it took to move the flap which could be used to crudely compensate for more boost or add more fuel for other reasons like cams, exhaust work, etc. I've ran into the same or nearly the same AFM on some early 90's Mazda's where the NA and Turbo engines used the same AFM housing, the difference was in the spring tension set on the flap. The turbo car had a heavier sprung flap and the NA car had a softer one, a cheap mod was to change the spring tension setting and crank up the boost with a vacuum bleed to the waste gate actuator. Easiest way to turn a 160hp car into a 180hp car for $5.

http://www.northbaymotorsports.com/tuningairflowmeter.htm Looks similar to the 3S-GTE flappy AFM's doesn't it?

[Smaay]

we are talking O2 sensors, not the maf assembly

3rd gen is MAP based, i didnt even consider the flapper MAF of the 2nd gen

This post has been edited by Smaay: Jul 8, 2015 - 10:07 PM

[4-eyed-freek]

So with all this being said would it be best to order an 02 from tcb or get a 2nd gen sensor from a alltrac from the dealership?

[Bitter]

I assumed AF sensor was Air Flow sensor not Air/Fuel sensor since most people call them Oxygen sensors or Wideband oxygen sensors.