O2 Sensor modification using spark plug non-foulers

[chewysdad]

Because of the venturi effect there would be a measurable drop in pressure around the sensor as opposed to the pipe. But with the sensor branch sealed the opening into the side of the exhaust pipe then just creates an amount of turbulance that would swirl some gasses around the sensor, but nothing like if it were sticking into the flow through the pipe.

[Redmeanie]

There you Go!

Sounds Like We Have Us A Working Theory Here!

[Redmeanie]

Simple A/F Ratio Meter

Here is a simple circuit if you want to see what the O2 sensor is actually reading. It is really easy to make and costs about $12 to make....Hope this helps everyone looking into this!

DIY Air / Fuel Ratio Meter



I made a public B.O.M. at Digi-Key because the parts list provided on the link were old.....Here it is if you're interested!

Part List(s)

[chewysdad]

This would be very useful. If a second O2 sensor socket and sensor were installed, then hooked up to this device, you could monitor what the ECM and engine with the "spaced out" sensor were actually doing.

[terence123]

Interesting stuff... but... There was a loooong time, that there was no O2 sensor in cars. And everything went ok (most of the time..), which makes me wonder... wouldn't those stories about burning valves etc. be fearmongering fairy-tales from big-oil? Do you know of anyone (outside racing) who had burned valves for using lean mixture?

just a thought.

[mrbreau]

It doesn't work for me!!

I did the hack last week and am seriously disappointed. It is a '90 Mazda pickup BTW. My mileage dropped from 22mpg to 16mpg! Though it may be because I only make short trips, ten miles or less, I would have thought the hack would work anyway. I'll be undoing the system today and go on to something else. Afterall, I can live with the 22mpg.

Warren
..

[Redmeanie]

Probably Why.............

How could you already know exactly what your MPG usage is if you have only done short trips and just did this last week?
Did you put this on your front O2 sensor?
Also are you running anything else to compensate for the fuel being cut? i.e a Booster Cell, fuel additive or specialized plugs?
If none of the above your probably putting your ecm into loop mode and now it is running in its programmed state.....This would be caused by too lean of a mixture and your knock sensor causing the ecm to revert to it's "safe" loop settings.....

****CAUTION**** "THIS MOD CANNOT BE DONE ALONE"

[Aaron]

no o2 sensors on older cars

Hi Terence,

I think before the o2 sensors, it would have been carbureted vehicles so no o2 sensor needed...just adjusting jets.

Were there any fuel injected cars that did not have o2 sensors? I don't know and if they didn't, how was the air/fuel mixture regulated?

[Aaron]

results with o2 sensor modification

I don't know what my personal results are yet because I still have 1/4 to 1/2 tank left. I don't drive that much and we have snow on the streets off and on so some spinning of wheels isn't fair for the test. Either way, I will report results.

Also, if a car drops mileage, I would first check to see if there is a true ground connection between o2 sensor and the vehicle's ground. If there o2 sensor is totally not connected, it will go default rich mode for "safety" to prevent damaging engine from being too lean.

I wouldn't think anti-seize lubricant, etc... would reduce a good electrical connection but simply testing with a continuity/ohm meter should tell.

[chewysdad]

Back in the day... 1971, I had a 64 Corvette 327 that I put a fuel injection unit on. Very primative compared to today's FI. It had a high pressure pump driven off the distributor with a flexible cable like a speedometer cable. It had some diaphragms that controlled the mixture. The car had a wild cam, no low end torque, but when the tachometer hit 2,500 rpm w/wide open throttle it would flop almost instantly to 5,000 rpm and the smoke would roll off the back tires. Dang, not very streetable but it sure was fun! Oh, no O2 sensor. That Corvette in stock 300hp 327 trim got 19 mpg on the highway.

[terence123]

I have a car with mechanical injection (1986) and have also a lpg installed. When the car is running lpg, the fuel pump is electrically disconnected. Although I have an O2 sensor, it does not affect the circuit when on lpg.

So for all people who have lpg, the admission of hydroxy does not need sensor tuning.

[Aaron]

results so far

So far the results do not look good. I have little less than 1/8th tank and about 200 miles. Last night the check engine light came on for the first time in 7 years that I've had the car. It went back off when I turned off the car and turned it back on.

I'll check to see if the o2 sensor mod is leaking, if the wire is connected and if there is a true electrical connection to ground.

I'll go through one more full tank to see what happens...quite a bit of the driving was spinning wheels on the snow/ice even with studded tires. Anyway, I'll report what happens.

[gabriolaman]

Interesting stuff... but... There was a loooong time, that there was no O2 sensor in cars. And everything went ok (most of the time..), which makes me wonder... wouldn't those stories about burning valves etc. be fearmongering fairy-tales from big-oil? Do you know of anyone (outside racing) who had burned valves for using lean mixture?

just a thought.

here is some info on this subject
info here

[HairBear]

I have seen this type of device before. But the device I saw had the sensor encapsulated in a dome. no holes. This may be why it is not working like it should. The object of the device to work is the oxygen content not fluctuating. Having the hole doesn't do a whole lotta good since the sensor is still in the stream. With a hole there is no isolation from the stream. I hope this helps.

Merry Christmas!

[Aaron]

seal the hole

This is a good point but it does seem that pulling it out of the stream would subject it to less oxygen.

It would be simple enough to weld the hole close on the bottom non-fouler as it is a pretty small hole. I don't have a quick easy way to weld this...perhaps I could put in a small bolt with a nut on the other side if there is space.

I do need to check my connections first before doing that. I do feel quite a bit more power so most likely, it seems it is running richer burning more gas.