Want to Install O2 Sensor in 99 Civic

[irfan44]

bump....

[atif11]

Bump for a good question , i want to know the same
the process i know is very expensive but very effective is installing O2 sensor and "wideband"
but want to know some cheap solution
or if i can get a wideband in cheap price

[hash4u]

got it done many years back in my 98 vti
it was part of cng lambda (nothing to do with how the car runs on petrol though)

[Xulfiqar]

dont bother - the o2 sensor you would be installng would be sourced from the junkyards anyway - even the brand new ones at new parts markets (khi plaza etc) are sourced from shersha junkyard. The trim pot works - and the whole tuning scene around the world always loves the trim pot rather than the fiddly O2.

[irfan44]

fidly or not, my question is how to get it done?
Will it work or not & will it control the fuel injection.
If we find it more fidly then efficient then we can always return back to trim pot.

[Xulfiqar]

your ECU will not have the heated O2 function - so for you a two wire sensor would work the output from the pot should be cut and lead to the ECU o2 input and the remaining wire would be sensor ground - green wires in the loom, (do not ground it to the body).

the O2 sensor/trim pot is only read if the engine coolant temperature sensor signals the ECU to go into closed loop mode - if you are running with no T-stat and direct fan the closed loop temperature is never reached and the ECU stays in cold run rich mode. So for efficiency's sake make sure your engine gets to normal temperature and the automatic fan works.

[irfan44]

My trim pot has three wires connected to it as under:
1. Green/White
2. Brown
3. Yellow
My guess is 1 wire should be signal wire, 2nd should be ref voltage 5v & 3rd must be the ground.
The problem is which 1 is which. Plz elaborate as per wire colors if u can.
& 1 more thing. normally O2 sensors produce 0.1 - 0.9v signal. but my guess is that the sensor required to replace this particular trim pot should be of 0-5v signal range as available in universal range. Am i right?

[ahsanonline]

your ECU will not have the heated O2 function - so for you a two wire sensor would work the output from the pot should be cut and lead to the ECU o2 input and the remaining wire would be sensor ground - green wires in the loom, (do not ground it to the body).

the O2 sensor/trim pot is only read if the engine coolant temperature sensor signals the ECU to go into closed loop mode - if you are running with no T-stat and direct fan the closed loop temperature is never reached and the ECU stays in cold run rich mode. So for efficiency's sake make sure your engine gets to normal temperature and the automatic fan works.

approx what temp does it have to achieve to get to closed loop mode?

[Xulfiqar]

approx what temp does it have to achieve to get to closed loop mode?

78 degrees celcius at the cylinder head.

[Xulfiqar]

My trim pot has three wires connected to it as under:
1. Green/White
2. Brown
3. Yellow
My guess is 1 wire should be signal wire, 2nd should be ref voltage 5v & 3rd must be the ground.
The problem is which 1 is which. Plz elaborate as per wire colors if u can.
& 1 more thing. normally O2 sensors produce 0.1 - 0.9v signal. but my guess is that the sensor required to replace this particular trim pot should be of 0-5v signal range as available in universal range. Am i right?

Green/white is the sensor ground
yellow would be sensor reference and the last is ground. Please verify with multimeter continuity check first. The reference ground is on every sensor you can check its continuity with them.

yes all japanese Denso/NTK sensors are of this range. You can make work with a proper 4 wire sensor but leave the heater element wires disconnected as it would be mighty difficult to source a 2 wire in Pakistan. This also has an inherent problem of the sensor not getting upto working temperature and hence providing no signal to the ECU.

[irfan44]

Here r the pics of TRIM POT under driver side lick panel.

[irfan44]

what abt the heater circuit. can we do some direct connections for it or some JUGAAR?

[Xulfiqar]

the heater is wholly controlled by the ECU anytime it senses the O2 sensor is in cold range. no way around it.

btw - for corolla owners - this pot is in the engine room - now I know people will try to lean out the engine and then we would have some interesting stories to read.

[ahsanonline]

sorry for being a litl off-topic, what can be said about the o2 sensor (single wire type) if its voltage is more or less stuck at 0.4v ?

[irfan44]

now I know people will try to lean out the engine and then we would have some interesting stories to read.

LOLx. yup everybody will do it. btw its our psychee, we fiddle with everything.
i m also one of them. its the best way to learn but background knowledge is a must.
wat if we opt for a 1 wire o2 sensor. how it can b incorporated or a 2 wire lambda sensor will be better.

[Xulfiqar]

the 1 wire sensor puts out an oscillating signal which your ECU wont understand.

[Xulfiqar]

LOLx. yup everybody will do it. btw its our psychee, we fiddle with everything.
i m also one of them. its the best way to learn but background knowledge is a must.
wat if we opt for a 1 wire o2 sensor. how it can b incorporated or a 2 wire lambda sensor will be better.

fiddling is good only if you first get to know whatever you are fiddling with. Otherwise you dont ride the learning curve, because the first effort for a learning curve is the one where your brain soaks up the most knowledge.

[kristopher.leger]

Hello , its a little bit late for the reply .. but i want to know something , i dont see the trim pot in my exi 99 civic and im running with no thermostat .. does this have some issues with my fuel economy ? And if i re instal a thermostat .. it will have better consumption economy ?

[irfan44]

Yes bro reinstall the thermostat. No argument on this. Your engine will thank you.
The trim pot is on the driver side footwell.

[RAJAO7]

what is the normal voltage of trimpot thing?